Rihoko Sakurai (桜井 梨穂子, Sakurai Rihoko) is one of the female protagonist of the story, and her story is in the 5th arc. She is childhood friends with Junichi Tachibana and Kaoru Tanamachi. She is a student of class 2-B.
She has brown hair and brown eyes. She wears their school uniform, but she wears a vest rather than the black coat. Her attire is similar to Kaoru.
She has a huge appetite and is also extremely clumsy, forgetting things with unusual ease. Her best friend is Kanae Itou, who is an extremely athletic girl. She is often seen in the library, reading dieting books and also a member of Kibitou Tea Club. She has an unrequited love for Junichi ever since childhood.
Rihoko is finding it hard to let Junichi know her true feelings. Junichi is forced into helping out the tea club for the founders festival (which Rihoko is a part of) by two tea club 3rd years Manaka Hiba and Ruriko Yuzuki. Since the two 3rd years will be graduating, they try and persuade Junichi to join to no evail. Howerver he does join in the end as a graduation gift and so Rihoko will not be alone.
Rihoko still has not confessed to Junichi so no real romantic progression has been made on Junichi's side.
Rihoko has her toenails cut by Junichi.
Junichi is suffering from fatigue, so Rihoko decides to cook Junichi dinner to cure it. Whilst shopping for groceries, Makabe (who is trying to get a girlfriend) confesses to Rihoko but is rejected. She says there is someone she likes which Junichi overhears (after following them),it is strongly implied that he hears Rihoko say she loves him but it is hard to tell as the sound of a train covers her confession. After dinner Rihoko is invited to stay over. She goes down stairs to meet Junichi looking into the night sky. They have a heart to heart, reminissing about the past. At this point Junichi realises his feelings and confesses to Rihoko before she could get the chance. They share a kiss and are then seen together drinking tea the next day.
In her route, she is portrayed as Junichi's childhood friend. She eats a little too much and believes herself to be fat. Has been with Junichi since elementary school and has a crush on him ever since.
Junichi spends Christmas with Rihoko and Miya in their house. Later outside, he tells her that he always took their relationship for granted, but now it's different. They share a deep, passionate kiss. Many years later in college, Junichi buys her a creampuff. Inside it, there's a ring and she accepts.
Junichi spends the school Christmas festival with Rihoko. He hugs and realizes how much she means to him. The next year, he joins the tea club but it's closed due to lack of members. Despite all this, she's with Junichi and that's all that matters.
Rihoko wakes Junichi up while in bed by jumping in his bed and going underneath the blanket. It reminds her of their childhood and the time they spent together and she feels that it will not change.
If Junichi stoods her up on Christmas, she forgives him. Junichi begs forgiveness from Rihoko (who caught a cold from standing in the snow) but she tells him that she was never angry at him and never can be. They proceed to kiss. A little while later, Junichi begs Rihoko to punish him. She makes him eat an all you can eat ice cream parfait. He faints and Rihoko smiles. They'll be best friends forever.
- Her Arc is the only arc wherein Christmas takes place in its third chapter and the only arc to feature the events after Christmas on-screen.
- She is the second of three Enterbrain heroines who are childhood friends with the protagonist followed by Haruka Niimi from Photokano, if one follows both Rihoko and Haruka Niimi's Respective arcs, the first one being Mao Mizusawa from Kimikiss.
- The only main heroine who Junichi doesn't love on the first season. And finally has her feelings accepted by Junichi on the second season.