Kenichi: The Mightiest Disciple (2006)

Kenichi is a timid high school student constantly bullied and lacking friends to defend him. His life takes a turn when he meets Miu, a captivating girl who embraces him and resides at a dojo run by six formidable martial arts masters. Drawn by Miu, Kenichi embarks on a rigorous training journey that challenges his limits. As he strives to endure intense workouts, he hopes to not only survive school but also win Miu's heart. While often seen as a weakling, Kenichi’s journey transforms him into an inspiring underdog ready to face his fears.