Kourin is a character in Cardfight!! Vanguard. She is the older sister of Rekka and the younger sister of Suiko. She helps them run the cardshop PSY, and is a member of Team Ultra-Rare. It is seemed as if she like Aichi. She challenged Aichi Sendou to a fight after he was able to activate the machine that made the cards virtual. She was unsure of Aichi's skill, thinking he was weak but decided to fight him anyway. After a close match she won, but told Aichi it was a good fight and told him he should enter a tournament.
She is next seen in Episode 16, as a hologram with her sisters, welcoming players to the regional tournament.
In Episode 18 she is singing with her sisters during a break at the tournament. After the song she was surprised to see Aichi make it to the finals.
Throughout the match between Team Q4 and Team Handsome she is commenting about the the matches with her sisters. During Aichi's match, she and her sisters agreed that Aichi was different during his fight against Gouki. They then gave Team Q4 medals after winning the tournament.
In episode 23 Sukio invites Ren Suzugamori to test his skills. Kourin fights him using the same deck he was to use in their fight. Although she had the upper hand for part of the fight, she eventually lost. Afterwards when they are talking to him he says she's a good fighter, but she's not on his level. Kourin get's angry at this but is held back by Sukio. As Ren leaves she says she will never acknowledge him.
As of Episode 72 Rekka and Suiko seemed to have noticed that Kourin is interested in Aichi,It is also humored that she is interested or she has a crush on Aichi