The obligatory class delinquent. Warning, she has all features of tsundere!

"The class delinquent. Yumi is barely ever in class and tends to cause trouble when she is, such as through bullying Futaba. She's extremely hostile to Sensei for his attempts to discipline her and may have ties with the local Yakuza. She can be found wandering the streets on weekend afternoons."

• - A description from the official Lessons in Love website.

From Lessons in Love - a videogame by Selebus.