Tooru Seino, a manga artist known only within subculture circles, finds himself in an extraordinary marriage to one of Japan’s most famous celebrities. Danmitsu is a non-fiction manga essay that chronicles the daily life of Seino and his wife, the actress and gravure model Mitsu Dan. The narrative begins by exploring the unlikely origins of their relationship, detailing how the couple started dating, the key episodes that led to their marriage in 2019, and the reality of their life together as a married couple. The project serves as an attempt by Seino to convey the truth about his wife's personality, including her profound charisma, unique sense of humor, and the more intense aspects of her character that the public may not see.

The setting shifts between the private, mundane spaces of their home life and the contrasting public world of Japanese entertainment where Mitsu Dan built her career. The central conflict stems from the vast gap in public recognition between the two spouses, prompting an exploration of how a celebrity known to everyone and a manga artist known to very few can exist as a couple. Mitsu Dan gained widespread notoriety for her starring role in the 2012 BDSM erotic thriller film Be My Slave, a role that defined much of her public image and adds a layer of cultural complexity to the couple's story. The manga seeks to present her not just as that public figure, but as a person, with Seino acting as her proxy to share her true self while she is not at full health.

Since its debut in Kodansha's Morning magazine on December 26, 2024, the manga has been met with significant critical acclaim. In a short period, Danmitsu has appeared on several major annual ranking lists. It secured the second position on the Kono Manga ga Sugoi 2026 list for male readers, a prestigious guidebook compiled by industry professionals. The work was also nominated for the 19th Manga Taisho Awards in 2026, further solidifying its status as a standout new release. The first compiled volume was released on July 23, 2025, and by November of that year, it had already achieved 100,000 copies in circulation across print and digital formats, demonstrating strong commercial success alongside its critical reception.