Rin is a second year student of Eiden school. She is very romantic and is a wonderful cook. Rin is viewed as the perfect housewife. She is usually seen together with her best friend Sakura. Rin is also very self-conscious and responded very negatively when Natsume called her fat. Rin is also shown to be a good judge of character.
Sakura loves to tease her, both with words and physical action. Rin never fails to entertain Sakura with her reaction but she doesn't let it affect their friendship.
Sakura and Rin were first seen on the first day in the school hall. The gossip involving Kazushi and the guys along with Hu-sen and Rei had already spread around the school. Sakura and Rin befriended the guys despite the rumor and defended them.
Sakura explained that breakfast was cooked by each homeroom group in turn. When the morning was Sakura and Rin's turn, Rin was revealed to be a wonderful cook and she made a hearty breakfast menu. Pierre praised her cooking ability and calls her the perfect housewife which made her very happy.
During the overnight experiment that the Principal made them do, Rin used a strand of Kazushi's and her own hair to disrupt the experiment and prevented it from causing further harm.
When Ran brought Kazushi to peep at Rin and Sakura at the public bath, Rin expressed her interest in Panchu and she explained that he has a nice personality behind his rebellious appearance.
On Mizuki's path, Mizuki was keeping her distance from Kazushi while she explored her feelings. Rin explained that Mizuki wanted Kazushi to approach her and egged him to further his relationship with Mizuki.
Edelweiss Eiden Fantasia
Rin was attracted to Kazushi. The class elected Kazushi as the class representative and Rin volunteered as the vice representative. Kazushi's friends urged him to pursue Rin.
Sakura was teasing Rin, Kazushi rescued her from Sakura and they ran to town for shaved ice. Rin made a wish at a Jizo statue. Rin revealed that she is the oldest of 5 siblings and she wanted the class to be like her family.
During alchemy class, Mei sent Kazushi and Rin to retrieve some instruments from the storage room. Several boxes fell and Kazushi protected Rin from them. He was hurt and was admitted to the nurse's office. At the office, Kazushi noticed that his Johnny had developed a face and arms.
Johnny told Kazushi that he was a god and that was considered as Eiden Island's guardian spirit. When the boxes fell on to Kazushi, his Johnny was damaged. He made the boxes disappear and possessed his Johnny to preserve it. He also explained that he can repair his Johnny given enough time and with Rin's help.
Rin moved in to Kazushi's dorm room with him named his Johnny Poko (a Japanese nickname for the Johnny). Kazushi's friends walked in on them and she announced that they were a couple. Yagami entered the room because they were making too much noise and Poko wiped his memory. The next night, Natsume suddenly appeared and inspected Poko.
2 days later, Haruka declared war on Kazushi's class because he did not allow her to join his class family since she was in a different class. She challenged them to a baseball game that Sunday. Both Yagami and Panchu were playing on Haruka's team and they were powerful players. Kazushi's class lost 40 - 0 and decided to clean the entire school as punishment. Appo, Ran, and Mizuki convinced Haruka to have a rematch the following Sunday.
Kazushi managed to win with a score of 2 - 1 but Poko was exposed. Rumors started to spread, saying that Poko could grant any wish. Kazushi started to receive many visitors at his dorm room. The island's denizens also started to experience minor earthquakes.
Eventually Mei and the Principal discovered that Rin had been staying with Kazushi at his dorm. Mei told the class that Kazushi will be punished by the Principal. The Principal took Kazushi to a secret room. She and Miya attempted to identify Poko. The Principal identified it as an homunculus and mentioned that she did not create it. Miya mentioned that it is a very advanced homunculus.
Rin became worried that Kazushi hasn't shown up after 2 days. The class pressured Mei to explain Kazushi condition. She revealed that he was kidnapped by the Principal. The Principal revealed that Eiden island had been held up with human sacrifice every 1000 years. After alchemy had begun being practiced, an homunculus was created as the sacrifice instead, and Poko was that sacrifice. She also revealed that she is going to cut Poko off to sacrifice it to save Eiden island.
Natsume suddenly appeared and rescued Kazushi. He was then admitted to the nurse's office. His Johnny had already been repaired.
Haruka revealed that Poko ran away. Poko led Kazushi and Rin to him in the forest. Poko then guided Kazushi and Rin to the base of Eiden island. He bade them farewell and explaining that he was hiding in the Jizo statue that Rin was praying to. He happy to be discovered by Rin and becoming their friend.
He wanted to fulfill Rin's wish to be a bride and lied about needing Rin's help to repair Kazushi's Johnny, to allow her to become close to Kazushi.
Rin was sad to see Poko go, but Poko revealed a legend that an homunculus who fulfills his or her duty will be reborn as a human.
Haruka heard about Rin's wish to become a bride and bought a wedding headdress for her.