Hiiragi Kyouichirou is a boy who travels from his provincial town to Tokyo to attend university. He carries with him his family's sword to protect himself. When he arrives in Tokyo, he becomes swept up in a plot by the Imperial army. (Source: ANN)

First loves are messy. While settling in as a shoujo manga editor at the famous Marukawa Publishing House, Ritsu Onodera is quite troubled. Working under the stern and superb Masamune Takano is hard enough as it is. However, Masamune is not only Ritsu's first love from middle school but he also suddenly declares that he will make Ritsu fall for him again. Unknown to them, another editor in the department, Yoshiyuki Katori, is in a relationship with the popular manga artist Chiaki Yoshino. The carefree Chiaki fails to notice, however, that his high school friend—Yuu Yanase—thinks of him as more than a friend. The stoic but caring Hatori will not surrender his love so easily. Falling in love for the first time when you are 30 is certainly troublesome. Shouta Kisa, yet another editor, is going out with 21-year-old Kou Yukina, an art student. Despite Yukina's assurances, Kisa cannot help but doubt whether someone like himself is truly worthy of his younger, "sparkling" boyfriend. [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]

Upon hearing news that his mother was on verge of death, Haru Kaidou—the eldest son of the family—flies all the way to Canada. The moment he arrives, he learns that not only did his mother fool him, but he is also supposed to take care of his adoptive brother, Ren Kaidou, an antisocial kid who feels more comfortable around dogs than people. Due to his new brother's distrustful nature, Haru initially has a hard time reaching out to Ren but their relationship eventually grows. He makes a promise to Ren: they will live together in Japan after Haru graduates from high school. However, due to an unfortunate accident, Haru loses all memories of the summer they spent together, including the promise he made. Five years later, expecting Haru to keep his promise, Ren arrives in Tokyo; but to Haru, Ren is just a random boy claiming to be his brother. [Written by MAL Rewrite]