In this promotional clip for PSP title Boku no Natsuyasumi 4 (My Summer Vacation 4), the game's little boy goes around asking why girls have breasts.

At the end of the clip, his exasperated father asks if someone can explain this to the boy.

But honestly, why-girls-have-boobs is a dumb question! The kid should be going around asking why boys have nipples. What is up with that?

Boku no natsuyasumi 4 will be released on Japanese PSPs early next month. The game lets players experience an idyll summer vacation filled with bug collecting, Japanese drum beating, swimming, fishing and irritating questions.