Dōsei
Tactics' debut adult social simulation game with Key's future founders.
Dōsei (同棲, meaning "cohabitation") is an adult social simulation game from Japan, developed by Tactics—a brand under Nexton. It launched for Windows PCs on May 23, 1997, the same day Leaf released *To Heart*. The game follows a branching storyline with preset scenarios and interaction paths, centering on the appeal of the sole female lead, Manami Minase. Players take the role of protagonist Masaki Yamada, who lives with Manami shortly after they finish high school. Masaki works to earn money, and when he returns home, he often has sex with Manami; this cycle of daytime work and nighttime sex repeats many times throughout the game.
A re-release titled *Dōsei Memorial Selection* came out on September 14, 2000. The original soundtrack was bundled with *Moon*'s soundtrack and sold at Comiket 58 in August 2000. Four staff members who worked on the game—Itaru Hinoue, Shinji Orito, Miracle Mikipon, and Shinory—later became founding members of the visual novel brand Key.
**Gameplay and plot**
*Dōsei* is a romance social simulation where the player controls Masaki Yamada. Most gameplay involves reading narrative and dialogue. The story branches into multiple endings, with the plot shifting based on player choices. Options appear at certain points, pausing the text until a selection is made. To see all plotlines, the player must replay the game and pick different choices.
The story begins on Sunday, September 14, 1997, with the two main characters living together after high school graduation: Masaki Yamada (whose name can be changed) and Manami Minase (also renameable). Two parameters change based on player decisions: Masaki’s physical and emotional strength, and Manami’s affection and lewdness. The protagonist’s money from his job also matters; the player starts with 100,000 yen.
The game includes numerous sexual CG scenes depicting Masaki and Manami having sex. Typically, Masaki comes home from work, has a short conversation with Manami, and then has sex with her. This repeats many times, so much of the gameplay occurs during sex scenes. Depending on choices, the protagonist may become unfaithful, unlocking sex scenes with five other women. The player can occasionally rest, but if Masaki rests too much, he goes bankrupt and the game ends.
**Development and release**
*Dōsei* was Tactics’s first game. Planning was led by YET11 (who also handled programming) and
- Developer
- Tactics (brand of Nexton)
- Release Date
- May 23, 1997
- Genre
- Adult social simulation game
- Platform
- Windows PC
- Notable Staff
- Itaru Hinoue, Shinji Orito, Miracle Mikipon, Shinory
- Re-release
- Dōsei Memorial Selection (September 14, 2000)
Lore & Background
Dōsei is a romance social simulation game in which the player assumes the role of protagonist Masaki Yamada, who lives with the sole female main character Manami Minase shortly after high school graduation. Gameplay follows a branching plot line with multiple endings; the player earns money at a job and returns home to have sex with Manami, a cycle that repeats many times. Parameters for Masaki (physical and emotional strength) and Manami (affection and lewdness) change based on player choices, and the protagonist's money (starting at 100,000 yen) is also a factor. The player may become unfaithful, unlocking sex scenes with five other women, and if Masaki rests too much he goes bankrupt and the game ends.
The game was first released on May 23, 1997, the same day as Leaf's To Heart. Planning was headed by YET11 (also programmer) and Don (scenario writer). Art direction and character design were by Itaru Hinoue, her second visual novel contribution. Computer graphics were handled by Hinoue, Miracle Mikipon, Shinory, and Suō Akiyama; Mikipon also worked on animation. Music was mainly composed by Shinji Orito, who had moved to Tactics after working under Leaf. Three others—Myū, Paste, and Ishisan—composed one third of the soundtrack. Dōsei was re-released on September 14, 2000 as Dōsei Memorial Collection, and later as a downloadable edition for Windows XP on June 3, 2011 by DMM.
Reader's Guide
Dōsei holds significance as the debut title of Tactics, a brand of Nexton, and as a precursor to the visual novel brand Key. Four staff members—Itaru Hinoue, Shinji Orito, Miracle Mikipon, and Shinory—later became founding members of Key in 1998, a studio renowned for emotionally impactful visual novels. The game's release date coinciding with Leaf's To Heart highlights a moment in the adult visual novel market of the late 1990s. Dōsei's gameplay, centered on a repetitive work-and-sex cycle with branching paths and multiple endings, exemplifies the adult social simulation genre of its era. Its re-release as Dōsei Memorial Collection and the bundled soundtrack with Moon at Comiket 58 indicate continued niche interest. While not as widely remembered as later Key works, Dōsei is a historical artifact of the talent that would shape a major visual novel studio.
Did You Know?
- Dōsei was released on the same day as Leaf's visual novel To Heart (May 23, 1997).
- Four staff members—Itaru Hinoue, Shinji Orito, Miracle Mikipon, and Shinory—later became founding members of the visual novel brand Key.
- The game's soundtrack was released bundled with Moon's soundtrack at Comiket 58 in August 2000.
- The protagonist's name Masaki Yamada and heroine Manami Minase can be altered by the player.
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