Pantsu ga Daisuki

Wataru is a student more interested in partying with friends than in working. His older brother is dead, but he continues to live with his sister-in-law Miwa and his nephew. As Miwa runs an underwear shop, Wataru is nicknamed Pantsu (meaning panties) by his friends. They are convinced that Wataru is in love with Miwa, but he denies it. However, the day he learns that Miwa is dating an older man with a family, Wataru begins to doubt: what if his friends were right? What if it's too late?