The police officer Shigemitsu Hashiba is a funny man. He never seems to take anything seriously. But this attitude is just a mask that prevents him from being truly known by others. All this will change when he is assigned as a partner to Keiji Sasaki, a diligent and too serious rookie. The two form a perfect combination and their goal is to arrest Mr Sawada.

A collection of bittersweet tales of all the different shapes an unrequited love can come in. Why is it so difficult to confess your love? Why is it that another person can affect someone else so strongly? When a powerful man is fickle, he is allowed to be. But if a woman is unfaithful, she is called a tramp. Koi tells the realistic stories of six different women of different ages, and completely different outlooks on life.