|Appearance||Period 22: The Land Of Mermaids|
Hatsuki has short black hair that frames her head with thick, brushed to the side bangs. A few hairs usually stick out. She wears half-rim glasses.
Nana notes that although she appears unkempt sometimes and is fairly plain, when she tries to groom herself she is actually pretty.
A thoughtful and sweet young girl, Hatsuki is very helpful and cares a lot about Nana's well-being and happiness. She admires her and looks up to her friends natural beauty and knowledgeable side, and she wants to be more like her.
Hatsuki was hanging out at the school pool with Nana as her friend silently fumed over how popular Yuina is with others. She notices this as the girls head out to change, and later she mentions that Yuina went missing as Nana reads a magazine in class. She recalls that Yuina had decided to check something by the pool that she forgot, but she's completely vanished. She suggests she and Nana should hand out the pamphlets she was in charge of but Nana blows her off saying she has something else to do.
The following boy, Hatsuki finds Nana again and Nana is shocked seeing how messy her hair is. She brings Nana into the nearby classroom as she informs her that she had been in a hurry and didn't realize it, so Nana begins to brush her hair and gives her a few tips on self-improvement; such as using treatment and remembering to put on sunscreen to avoid getting tanned. Hatsuki was delighted by her kindness and she pointed out how much she liked her because of her efforts, but her compliments went unnoticed.
By this point she was suspicious of how often Nana would disappear, and her suspicions were further confirmed after finding her at the pool. She gently chastises Nana, reminding her of how dangerous this is as she goes on to wonder if Nana really believes in the Land of the Mermaids. In hopes of getting her to stop thinking about it, she brings up what her mother told her- in that the girls who vanish aren't taken by mermaids, they drown. While this alarms Nana, she refuses to believe it as Hatsuki can't explain why heir bodies are never found. She tries to convince her to leave but Nana shoves her back, causing her to fall into the pool and sink down in it, with only her glasses floating back to the surface.
After Nana finally thought she found the mermaid again she was horrified to find that it wasn't really a mermaid- but a chain of pretty girls who had drowned beneath the water and dragged down anyone they deemed prettier than they. She is horrified after seeing Hatsuki floating on the top and she quickly tries to escape from her. But she is caught by the chain, and Hatsuki hangs onto her until she becomes one of them.