When she was a kid, Ai Sato (Fuka Koshiba) was beautiful and popular. Her first love was Sosuke Hasebe, a chubby boy with a tragic past who was frequently picked on, and who came to look on Ai as his protector and saviour. Time passes. Now Sosuke (Kento Nakajima) has become a handsome and high-powered publishing executive, while Ai has lost confidence and struggles to settle down. He gets in touch to rekindle their friendship but Ai backs out in fear, and ask her friend Risa Kiriyama (Yui Sakuma) to pretend to be her...

Now working at the same company, Sosuke little suspects that Ai is the previous love of his life. Ai initially tries to avoid Sosuke, but they are repeatedly thrown together and Ai quickly sees an aggressive side to Sosuke's character which wasn't there many years previously. Meanwhile Sosuke unsupsectingly continues his new friendship with Risa, thinking her still to be Ai. The real Ai finally loses it with her boss...

At work Ai confides in her colleague, Takuya Higuchi (Eiji Akaso), after he discovers that Ai and Sosuke were at school together. Ai is quickly discovering how important her previous self was to Sosuke, and despite herself cannot help making connections with her own past. For her part, Risa is now in serious danger of falling for Sosuke, as they spend more time together. She also confides in Takuya without realising that he works with Ai. Meanwhile Ai discovers that Sosuke's role in the company is to try and prevent the magazine being closed down and she is galvanised into action...