Gentaro is my best friend.

Genki is my best friend.

Kinetic energy is directly related to the speed of an object.

The use of renewable energy helps protect the global environment.

A nuclear submarine can travel underwater for a long time.

He is collecting old British shilling coins.

According to mythology, it is said that the 'shirikodama' resides in the human anus.

My butt hurts because I've been sitting for a long time.

He felt pain in his buttocks.

I want to go to Sicily.