Because I Don't Like My Big Brother At-All--!! – Folge 7

Shūsuke and his friends go on a trip to Akihabara in search of adult goods while Nao and Iroha decide to follow them. After visiting an adult DVD store, the group gets into an argument about their desired fetishes and break off in search of them, leaving Shūsuke alone. However, they soon come to apologize to each other and go to a maid café holding a 'little-sister' service.