19 (Post-time skip)
|Birthday||July 3 (cancer)|
|Height||5'3 (160 cm) (at 14 years old)|
|Eye colour||Ocean aqua-blue|
|Hair colour||Smoky purple|
|Status||Alive | Student (formerly), Nurse (currently)|
|School||Nami Elementary (formerly)|
Nami Middle School (formerly)
Mihama Middle School
Isamu Kihara (Adopted grandfather)
Tsumugu Kihara (Isamu's grandson)
|Friends/Allies||Hikari Sakishima (Childhood friend)|
Manaka Mukaido (Childhood friend)
Kaname Isaki (Childhood friend)
Tsumugu Kihara (Close friend)
Miuna Shiodome (Close acquaintance)
Egawa Takeshi (Classmate)
Sayama Shun (Classmate)
Sensei (Close acquaintance)
|Relationships||Hikari Sakishima (Former crush)
Tsumugu Kihara (Boyfriend)
|Manga Debut||Volume 1, Chapter 1|
|Anime Debut||Episode 1: "In Between the Sea and the Land"|
|Japanese Voice||Ai Kayano|
|English Voice||Brianna Knickerbocker|
Chisaki Hiradaira (比良平 ちさき, Hiradaira Chisaki) is a main female protagonist in the series, along with Manaka Mukaido. She is one the students at Shioshishio and the childhood friends of Manaka Mukaido, Hikari Sakishima and Kaname Isaki.
She is secretly in love with Hikari, but she hides her feelings due to the fact that he is in love with Manaka and Chisaki is afraid that it will ruin their relationships. Chisaki is the only person among her Shioshishio friends who avoids hibernation after the Ofunehiki festival. Since the Ofunehiki festival, she has been staying with the Kihara family and also studying at a nursing school. When she reunites with her Shioshishio friends, she feels left out as she is now much older than them. Chisaki fears change, and feels guilty for having lived a relatively happy life during the time skip despite the absence of her friends. She has been pretending to have her "old feelings for Hikari" as a means of claiming she hasn't changed over the past five years, but she really is in love with Tsumugu Kihara. They then become a couple. In the last scene, her now-healthy and former guardian Isamu Kihara states that she can now return to the sea to live with her parents if she wants, now that everyone has re-awoken. Nevertheless, she still chooses to remain in the Kihara residence with Isamu, as Chisaki's mother even offered to teach her some nutritious meals to help keep him healthy and watched over, while Tsumugu is away for college.
Chisaki is a beautiful fair-skinned young woman who has a complex about her "oversized" body.
Before the Timeskip
Chisaki has long, wavy purple hair that she usually wears in a high-side ponytail on the left side, aside from two thick locks of hair next to both sides of her face that reach her shoulders. She has short bangs that hang to her eyebrows. Her eyes are blue like all the people from the sea. To her embarrassment, she is commonly described as curvaceous and she usually gets attention from boys because of it.
Chisaki is usually seen wearing her school uniform, but wears other clothes from time to time, too, like long skirts and blouses. Chisaki wears her uniform with a pair of white crew socks with blue rims and decorates her ponytail with a cornflower blue scrunchie-style hair tie with an attached pair of white ribbon.
After the Timeskip
Chisaki becomes taller and more curvaceous, she cuts her hair to shoulder-length and it is slightly wavier than it was before the timeskip. She wears it down with a small side braid tied with tiny blue bows on the right side.
She usually wears casual sweaters and denim shorts and skirts with thigh-high socks. She is occasionally seen in a pale purple pajama set, which she sometimes wears loose twin tails with. Sometimes she is seen in her nurse uniform. She also seems to prefer high top shoes.
Chisaki is a kind, cheerful and mature girl who cares a lot about the people she loves. She doesn't want to let her friends change because she fears that if her friends change, their relationships would become different. Despite her usually non-violent nature, she can have the occasional angry and annoyed outburst. She is very calm about situations too.
When Manaka Mukaido and Chisaki were kids, there was one time they got lost. They had gone to the outskirts of the village into the outer sea to look for coral. Unable to find home, the two were saved by Hikari Sakishima and the feeling of him holding her hand caused her to have developed feelings for him.
On their first day of going to school on the surface, Chisaki walks with Kaname Isaki and Manaka Mukaido who greets Hikari Sakishima just as he arrives and runs past her. Seeing him berate Manaka for wearing the uniform of the surface school rather than that of their underwater school, Chisaki gets between the two of them and tells him to leave her alone. Manaka decides to change, leaving Chisaki and the boys to go on. As they arrive at the surface, Chisaki leaves with Kaname for school but on the way they see that Manaka has been caught up by mistake in the net of a fishing trawler.
At school, Chisaki takes part in introductions in the morning before having to break up another argument between Hikari and Manaka. Later, she gives her P.E. clothes to Manaka to help her stand out less, telling her she has no use for them and advising her that Hikari truly cares for her. The two girls then look out the window at the running track and spot Hikari racing Tsumugu Kihara, quickly losing his footing and knocking both of them down.
The next morning before school, Chisaki and the group arrive to pick up Manaka from her house but find that she refuses to come out, forcing Hikari to go get her. At school, a group of girls take Manaka into the sun to inspect her supposedly shining skin. Chisaki attempts to stop them but is unable to do so as Manaka is quickly embarrassed and makes a run for it. Notifying Hikari and Kaname, the three go looking for her.
Looking through the city, Chisaki and the group come to the conclusion that Manaka did not return home. As they notice their skin beginning to crack from sun exposure, the three take refuge in the water temporarily, before Hikari leaves to continue the search alone. As Chisaki begins worrying about him, Kaname comments that she and Hikari look like parents to Manaka and tells her if anything happens to Manaka, she will be next to his side. This upsets Chisaki as she tells him that he's not funny, adding that she loves Manaka and does not want anything to happen to her.
At the beginning, Chisaki disliked Tsumugu because Manaka Mukaido seemed to be in love with him and she feared that this would cause the group to "change" by drifting apart. However, after interacting with him and coming to an understanding, the two become much closer, so much so that she dives into the ocean to save him after his boat is capsized by a large wave from the Sea God during the Maiden Sacrifice. She proceeds to save him with the assistance of Kaname Isaki, cradling him in her arms once he is safe.
Years after the freezing of the sea, their relationship has developed. They are now living together and seem to have a special bond, seeming to understand each other on a more personal level and are shown to perform household tasks in sync with one another, much to the ire of Kaname who begins to feel jealous of this new bond. After the 5 years they spent together Tsumugu admits to Kaname that he is in love with Chisaki. He even thought it would be better if Manaka, Hikari Sakishima and Kaname didn't wake up because he was scared that Chisaki would disappear from him. After overhearing an argument between Hikari and Tsumugu she discovers that he is in love with her, shocked she jumps into the sea where he tries to follow. After following her, he confesses his feelings for Chisaki and tells her that she was like the beautiful sea. Chisaki rejects his confession and yells that she is not in love with him and runs away.
When walking back home, Kaname talks with her and Chisaki admits her feelings for Tsumugu by lamenting about how quickly she fell in love with him, after only being together for five years, in comparison to having been with Hikari and the other since they were born. Kaname tries to help Chisaki realizing her true feelings though Chisaki believes she isn't allowed to love Tsumugu due to her loyalty to Manaka, whom she thinks has feelings for Tsumugu. Chisaki also thinks that by admitting her love for Tsumugu, she would be betraying everyone that was still sleeping. Chisaki insists to Kaname that she is in love with Hikari no matter what, despite the fact that Hikari still loves Manaka, even though she's lying to herself. She also believes that she can't accept Tsumugu's feelings since Tsumugu is needed in order to awaken Manaka's "feelings of love" for him. With Kaname's help, Tsumugu finally revealed the truth to her that Manaka is actually in love with Hikari, which leaves Chisaki shocked and conflicted, telling herself that she's "awful", because she prevented them from being together only because she didn't want anything to change between them, but in truth, she wanted them to be in love with each other, so they can stay together. Tsumugi tells her that's no longer the case and the real reason is because she is in love with him, which she neither confirms or denies. When Tsumugi finally tells her he loves her and hugs her, she is still conflicted as she believes she shouldn't be the only one out of her friends to achieve happiness, but allows him to hold her. Eventually, the two become a couple as Chisaki decides to follow her feelings and find happiness for herself.
Chisaki is the best friend of Manaka, and they were always together in the past. Chisaki helps and protects Manaka, because she doesn't want Manaka to change, in fear of the group going their separate ways. It was also very hard for Chisaki to be with Manaka because Chisaki has strong feelings for Hikari, although he loves Manaka, and gets upset at herself whenever Manaka helps Hikari with his problems, and that she stood up for him ahead of her. She can't accept Tsumugu's feelings because she thinks Manaka is in love with him. However, she learns Manaka actually loves Hikari and the only reason she kept it from everybody was that she thought it would make Chisaki sad. This causes her to feel remorse, as her feelings for Hikari prevented them from being together and the only reason she kept her feelings because she didn't want to change her friendship between them, but allows her and Hikari to be together without interfering.
Early in the series, Chisaki has romantic feelings for Hikari, who is also one of her childhood friends. She admires his ability to change those around him and his will to fight and stand up for himself and others, but feels frustrated whenever she is unable to help him in his problems, and that Manaka is the one that helps him, and complains to herself how useless she is to him. Despite this, Hikari does not feel the same way and only sees her like a sister and her feelings for him is one-sided. Later, Chisaki decides to confess her feelings for Hikari, but after finding out that Hikari is in love with Manaka, she becomes upset and holds back admitting her feelings, not because he would reject her, but because she didn't want their relationship to change, and eventually realizes that Manaka means a lot to him and that she herself has no place in his heart and she fell in love with him who already loves Manaka, and she shouldn't lie to herself anymore, that telling him her feelings is enough, and tells him to go after Manaka. However, he remains oblivious of her feeling to him, responding that he too didn't want to change their friendships between them, and they never mention this again.
After the time skip, she has gotten over him, but she doesn't want to change so she tries to make herself like him again. She made sure that she wouldn't forget that she was in love with him. When Chisaki learns of Hikari's return, she refused to meet with him at first, because she's afraid of how Hikari will react upon seeing her, but they later meet up and she then apologizes to Hikari for changing so much, but Hikari says she hasn't changed at all, which leaves her shocked, but is angry that he's still the same when he teases her. They don't interact much afterwards. After finding out that Tsumugu is in love with her, she turns him down and Kaname encourages her to be honest with her feelings, but she claims that doing so would betray any feelings she had for Hikari, despite knowing he still loves Manaka. Soon, she finds out that Manaka was in love with Hikari by Tsumugu, this allows her to officially move past from her unrequited feelings for Hikari, because she knew they were meant to be together and where Chisaki realizes she is actually in love with Tsumugu.
Kaname and Chisaki have been good friends since they were kids. They often look after each other, and Kaname has a crush on Chisaki, although he knows about Chisaki's feelings towards Hikari. When Kaname confessed to Chisaki, she was surprised and didn't know how to act when she was with him. He even said after he wakes up from the hibernation his feelings for Chisaki won't change. During the maiden sacrifice, Chisaki and Kaname dove into the ocean to save the drowning Tsumugu, after the large wave from the sea god caused his boat to flip over. Chisaki and Tsumugu managed to get back onto a nearby boat, but just as Kaname was climbing onto the railing, he was shocked to see Chisaki hugging the unconscious Tsumugu. His brief moment of shock caused him to lose his balance on the rail due to the boat making a sharp turn to avoid a nearby falling pillar, and Chisaki could only watch Kaname as he fell back into the sea while Kaname gave her one last smile just before he disappeared. After the time-skip, Kaname awakens to discover that Chisaki had avoided the hibernation, and she is now biologically five years older than him. He then moves in with Tsumugu and Chisaki for the time being, and he appears to get jealous whenever he sees Tsumugu and Chisaki together, meaning he still has feelings for her. He tries to convince Chisaki that her new appearance doesn't bother him or the way he feels about her, but he also unknowingly upsets Chisaki while commenting about how much adult-like she's become. Nevertheless, he helps Tsumugu by telling the truth about Manaka loving Hikari, so she can move past those feelings and so that Tsumugu and Chisaki can be together while he moves on with his own feelings.
- The first name Chisaki is written in hiragana (ちさき), which has no special meaning.
- Chisaki's surname Hiradaira means "ratio, proportion" (比) (hi), "good, virtuous, respectable" (良) (ra) and "flat, broad, level, even, peaceful" (平) (taira/daira).
- Nagi no Asu Kara Anime: Episode 1