Capturing: Dirty Foreplay (1989)

Original title: 監禁　ワイセツな前戯

Sho is a loner who works at a small factory. He has no friends, hardly associates with his work-mates and is regarded as a weirdo because of his love for gun models. One day he buys a real gun from a local yakuza. This boosts his self-confidence and he overcomes his insecurities and presents a bouquet of flowers to Eiko, who lives in a classy apartment and with whom he had fallen in love.