Koyurugi Sota looks up to and adores his senior in school, Takahashi Saeko. With his one-sided love for her, he decides to leave for Paris to learn the art of making chocolates, as she loves chocolates. After returning from Paris, Sota dreams of creating the perfect chocolate to present to Saeko, and that it will make Saeko fall madly in love with him. Saeko, who is already married, is actually quite the airhead, but her actions seem to lead Sota on. Does Saeko not know that Sota is madly in love with her? Or is she just playing with his feelings?
Heartbroken by his cheating girlfriend Takahashi Saeko, Koyurugi Sota goes to Paris to work as a chocolatier. He then returns after six years to open a shop "choco la vie", when his ex-girlfriend suddenly show up asking him to make her wedding cake. Even though he is still in love with her, he accepts her request.
Sota changes his attitude to a bad-boy to attract Saeko, but he ends up fighting with her when she asks him if he would go to a blind date with her friend. After the fight, Saeko stops coming to the shop. Sota wanting inspiration after losing Saeko, goes to his rival birthday party Rikudou. There he meets a model called Kato Erena and ends up spending the night with her.
Sota and Saeko reconcile. Tréluyer realizes his felling toward Sota's sister, Matsuri, and decides to wait until she breaks up with her boyfriend. But his feeling get the best of him, and he kisses her. He then decides to confess to her. Erena goes to her one-sided love's concert, Kaoruko got invited to a dinner date, and Saeko invites Sota to a date.
Olivier gets rejected by Matsuri. Sota started asking Rikudou about Sekiya to set him with Kaoruko after she rejected him, but Rikudou misunderstands and thinks Sota is gay. Saeko feeling lonely by her husbands attitude, invites Sota to her house after the date, but Sota rejects her. Eventually, Kaoruko agrees to go on a date with Sekiya, when she finds out that it is just a homework from Rikudou.
Saeko requests a birthday cake from Sota and stops coming to the shop because she is trying to be a good housewife, but instead gets injured by her husband. Erena gets an offer to be in the PV of her crush, Kurashina. Kaoruko hears about Sota sleeping together with Erena. Sota skips the shop party and goes to search for Erena after hearing her cry in the phone after confessing to her crush, making Kaoruko fight with Sota.
Erena gets rejected by her crush and Sota realizes why he couldn't forget Saeko. He reconcile with Kaoruko and decides to give up on Saeko, by confessing his feelings on valentine's day and move on. Matsuri breaks up with her boyfriend and decide to go out with Olivier. Sota also tells Erena that after he confess he wish to have a proper relationship with her.
The shop starts getting busy before the upcoming valentines day. Olivier goes with Matsuri to her ex-boyfriend's house to get the thing she left there. Olivier and Matsuri have their first kiss. Sota confesses to Saeko to properly end her feelings, but then Saeko started crying, making Sota believe that is her respond, and he kiss her.
Sota is confused after kissing Saeko. Saeko's husband get jealous after knowing about the Sota's chocolate and slaps Saeko. Saeko runs away and stay at Choco la vie, Sota then leaves her alone and go to Erena but forgets his phone. When he comes back for the phone, Saeko gets naked and starts kissing him and they end up having sex.
Erena is sad that Sota haven't contacted, she then goes to see Sota, but Kaoruko tells her that Sota is with Saeko. Sota feels lonely because he doesn't know Saeko feelings toward him. Kaoruko keeps getting annoyed by Saeko and plans to kick her out. With the help of Saeko, Matsuri decides to go over-night trip with Olivier. Yoshioka visits Sota shop asking if they know where Saeko is.
Sota realizes that Saeko doesn't actually love him, and he started wandering if she is using him. Olivier and Matsuri go to Kyoto on a trip and they finally have sex. Sota becomes a candidate to replace the old Bonheur main shop chocolatier, but eventually gets rejected, he finally realize he never had a real goal. Saeko starts helping Kaoruko to get Sekiya. Saeko's husband tried to take Saeko back against her will but Kaoruko helps her. Saeko turned out to be pregnant.
Erena finally confess to Sota. Saeko tells Sota that she is pregnant and it is not his child and that she never loved him, then she went back to her husband. Sota realizes he lost all inspiration and closes the shop. Kaoruko confesses her feelings to Sota and tells him she wants him to continue being a chocolatier. Sota determined to make chocolate without Saeko, tells her he will not meet her again. Erena dumps Sota first. Sota goes to Paris and leaves the shop to Kaoruko and Olivier.