This is a sub-genre of the romantic-comedy genre. To qualify, you have to have a single, dateless, nice guy who suddenly finds himself surrounded by a bunch of hot girls/women who are interested or attracted to him to varying degrees. The male lead may also live with many of these girls.
A story in which the main character is confronted with issues related to their transition from adolescence (innocence) to adulthood (responsibility). Most typically found in a modern romance story in which the main character has to confront his/her feelings over their first love.
(/the mild form for pervert or perverted/) This are non-pornographic anime titles which have a high amount of fanservice, nudity, or other sexual content.
