Boku wa Ai wo Shoumei Shiyou to Omou.

Synopsis

Technology wins in all matters of romance and love. Let me teach you the ultimate technology to captivate women, "Love Engineering"! Watanabe, a 26-year-old patent attorney, is shocked when his beloved girlfriend Maiko cheats on him. He is depressed by the reality that nothing is going well and drowns himself in alcohol at a bar. Then, suddenly, Nagasawa, whom he met at work, appears and he witnesses him captivating a beautiful woman on their first meeting in an instant! Nagasawa tells Watanabe, who is chasing him, about the existence of the ultimate technology to be popular. (Source: Kodansha, translated)