Tightly clutching his Gibson guitar, Mafuyu Satou steps out of his dark apartment to begin another day of his high school life. While taking a nap in a quiet spot on the gymnasium staircase, he has a chance encounter with fellow student Ritsuka Uenoyama, who berates him for letting his guitar's strings rust and break. Noticing Uenoyama's knowledge of the instrument, Satou pleads for him to fix it and to teach him how to play. Uenoyama eventually agrees and invites him to sit in on a jam session with his two band mates: bassist Haruki Nakayama and drummer Akihiko Kaji. Satou's voice is strikingly beautiful, filling Uenoyama with the determination to make Satou the lead singer of the band. Though reticent at first, Satou takes the offer after an emotional meeting with an old friend. With the support of his new friends, Satou must not only learn how to play guitar, but also come to terms with the mysterious circumstances that led him to be its owner. [Written by MAL Rewrite]

With an actress mother, producer father, and rockstar brother, anyone would expect Izumi Sena to eventually enter showbiz himself. However, aside from a commercial for a wedding magazine when he was a child, Izumi has never been in the spotlight; instead, he aims to become a manga artist. But a decade after the shoot, the magazine calls for a 10th anniversary ad, requesting the original child actors for the project. This reunites Izumi with Ryouma Ichijou, now a popular actor who, much to Izumi's shock, has been in love with him ever since their first meeting! However, due to Izumi's feminine appearance and unisex name, Ryouma believed the boy was a girl and continues to do so to this day. Izumi's troubles are just beginning, because even after discovering the truth, Ryouma can't seem to shake off his feelings... [Written by MAL Rewrite]

Takato Saijou has held the title of "Sexiest Man of the Year" for five years running. He is an accomplished actor, with 20 years of experience under his belt, and is aware his good looks are well above average. Proud of his career, Takato regards the title as an appropriate indicator of his success. But when his reign is ended by acting newbie Junta Azumaya, who debuted only three years ago, Takato's initial shock gives way to jealous hostility. Even in the new drama that he has been cast in, Junta seems to have suddenly surpassed him; snatching Takato's usual spot of lead actor, Junta continually manages to get on his nerves. Most infuriating of all are the bright smile and kind words that accompany everything Junta does. All this animosity comes to a head, however, when Junta catches Takato in a rather vulnerable drunken state. Endangering his own public image, Takato confronts the junior actor with harsh words and angry comments—an opportunity Junta takes every advantage of. With the famous actor Takato Saijou now on video picking a fight with a co-star, Junta has the perfect means to blackmail him. Asking the price of his enemy's silence, Takato is shocked to find that his motivation lies far from advancing his career; instead, Junta's terms are those that can only be realized in the bedroom! [Written by MAL Rewrite]

After having to deal with jealousy from his co-workers for working under his father's name, prideful literary editor Ritsu Onodera is determined to establish himself in the industry. To accomplish this, he quits his job at his father's publishing company and transfers to Marukawa Publishing. But instead of being placed in their literary division, Ritsu finds himself working as the rookie manga editor for the Emerald editing department, a team that operates under extremely tight schedules in order to meet deadlines. There, Ritsu is introduced to the infamous editor-in-chief Masamune Takano, a persistent man who strives for results. As it turns out, Takano is actually Ritsu's high school love, and it is the aftermath of that heartbreak has caused Ritsu's reluctance to fall in love again. Now with the two reunited after several years of separation, the reestablishment of their relationship is marked by Takano's vow to make Ritsu say that he loves him again. Sekaiichi Hatsukoi follows three couples that are interconnected within the manga industry, with each being subject to the budding of first love. [Written by MAL Rewrite]