Harumi Sakuraba (桜庭 晴海 Sakuraba Harumi) is the first girl to meet Koutaro. She is the president of the knitting club. In 8.5 and later volumes, it's revealed she's Alaia's promise to Koutaro as well as her reincarnation.
Harumi came from a very wealthy family. She's kind and well-mannered lady towards others. Her body is weak so she visits the hospital on a regular basis. While in the hospital, she became acquaintances with Kanae and her daughter Sanae (though only the modest one) due to them being in the same sickroom. She is thankful to Koutaro for saving the knitting club from disbanding.
Harumi is a beautiful girl with black hair and purple eyes. Her hair extends to her waist and her bangs are split apart, with most on [her] left side. She also sometimes wears hairpins.
She has a slim, weak and frail body due to having a chronic disease and not being active in physical activities.
While she's not always being noticed, she has the beauty and personality that many male students confess to, especially after the play.
She's described by Yuichirou as 'someone who exudes gentleness'.
She first meets Koutaro in March 1, when the clubs were recruiting. When a persistent student tries to make her go out with him, Koutaro manages to drive him away, and she develops a crush on him. He later applies when he hears this is the knitting club.
She became friends with Yurika when she tripped and helps her up. They also meet up at the marathon and after some troubles, manages to cross the finish line with her and Koutaro.
She meets up with Koutaro and the others at the beach near their summer house and indirectly makes the others angry of Koutaro when he was ignoring them. While looking for Sanae, Koutaro meets her and discusses about it. She manages to convince him when she reminded him that they were also strangers to each other when they first met.
She is later given the role of the Silver Princess for the Blue Knight play, though she can only act perfectly when around Koutaro, thus he is promoted to the role of Blue Knight. She then sees Koutaro and Theia and was jealous on how their relationship was working. They all later perform for the play at the festival.
Meeting up with Yurika, she discusses on wanting to get closer to Koutarou. She's later used as a hostage by Maki to Yurika. After Yurika was heavily injured, she, with a sword crest on her forehead, uses magic and makes a sword so Koutaro can defeat Maki but later collapses and forgets the event. She then walks home with Koutaro and Yurika. After the incident, she visits an aquarium with Koutaro, Yurika, and Kenji, where Koutaro teases her from time to time.
Kiriha invites her later to a Harukaze Man Hero Show as the civilian that Baron Demon (Koutaro) kidnaps from her boyfriend (Kenji) and forces her to marry him, though she smiles when she heard the word 'marriage'. While saying the cue, the Red Rangers unexpectedly appear and after some time, Harukaze Man and Kisshou Lady (Shizuka) finally appears. The following day, she talks with Koutaro about the play the other day.
While getting ready for Christmas, she (along with Koutaro) prepares the club room for the party. Though there's a difference between the LN and the Anime:
Light Novel: After inviting the Cosplay Club and Ruth in helping the preparations, they later surprise Yurika, Theia, Kiriha, Sanae (who was tagging along), Shizuka, and Kenji, and had a party in the club room.
Anime: She, Shizuka, and Kenji made a plan to not use the club room and use Room 106 instead. When Koutaro finally returned, Sanae, Yurika, Theia, Ruth, and Kiriha end up surprising him instead. The three later revealed that this was their plan, and they had a party in Room 106.
After the party, she walked with Koutarou. Along the way, he gave her a hand-made muffler and tries it on. She asks if it suits her and Koutaro jokes it doesn't. She then acts like the Silver Princess and gives him her present (knitting needles) in a similar manner to the Alaia giving the Blue Knight Signaltin. They then laugh together and look up as the snow starts to fall.
While preparing for the second part of the Blue Knight play, she helps Yurika in getting to her role as Alunaya. While she and Koutaro were practicing their lines outside, Clan tries to attack Koutaro again (without him noticing), but she (with the sword crest on her forehead again) blocks her attack when she noticed Clan and activates an Ancient Forthothian magic. Clan then retreats and Harumi can't remember what happened, but Koutaro laughs when he saw her reaching her palm to the sky. While she's acting in the play, Koutaro vanishes with Clan and the Cradle outside the gym. The sword-shaped crest on her forehead let her know that he vanished and in accordance to the manuscript, ran across the stage and prays that he'll be safe. After Koutaro finally returns, she started feeling anxious. Though after seeing Theia, she entrusted herself to these feelings to perform and the three later perform the 'Parting Scene'.
In the third term of high school, she receives a love letter and discusses to Koutaro about it. She later asks that 'if the girl that [he] fell in love with was in love with someone else, what would [he] do?'. After hearing his answer, she decided that she will properly decline the letter. They then talk about the school trip that he is gonna go to.
With Valentines Day approaching, Yurika asked her if she's gonna give Koutaro chocolate. She decides that she will give him chocolates and experiments which flavor he likes the most. In Valentines Day, she gives Koutaro his (true love) chocolate and Kenji's (obligation) chocolate. She then leaves to go to the hospital to give the others chocolates.
Koutaro saved Harumi's knitting club by becoming a member. When she was recruiting a guy, he tried to get her to be his girlfriend in exchange of joining her club, she tried to refuse but he didn't budge. Koutaro made a bold move to make him run away. After that incident Harumi developed feelings for him.
They became close after the clubs relay race. Harumi is the first person to believe that Yurika is a magical girl. She boldly asks Yurika for helping her to get close to Koutaro