Steven Reynolds 
After months of anticipation, the anime adaptation of the action-romance manga MARRIAGETOXIN has locked in its official premiere date: April 7th, 2026.
The announcement comes from the series’ official channels, after the anime had previously announced a ‘some time in April’ release, and has been widely shared across social media outlets, bringing one of Spring’s most talked-about debuts into focus.
The MARRIAGETOXIN plot
MARRIAGETOXIN, titled in Japanese as Marijjitokishin, originated as a hit web manga written by Jōmyaku and illustrated by Mizuki Yoda, and serialized in Shōnen Jump+.
The series has since garnered attention for its unique mix of action, comedy, and romantic themes as it follows an assassin’s unconventional journey toward love and marriage.
The anime tells the story of Hikaru Gero, a lethal but socially inexperienced member of the Poison Clan of assassins. When his family forces the issue of marriage to continue their bloodline, Gero enlists a notorious marriage swindler, Mei Kinosaki, not to marry him outright but to train him in the art of romance.
But, of course, things don’t go quite like Gero planned, who soon finds himself involved in a very strange partnership indeed.
From then on, this oddball pairing drives much of the anime’s charm and humor, blending high-stakes action with heartfelt and funny moments.
The recently released MARRIAGETOXIN trailer will introduce some of the anime’s incredibly quirky characters, and give you an idea about what you can expect.
The MARRIAGETOXIN studio and creative team
The anime adaptation is produced by Studio Bones (My Hero Academia), a studio with a strong track record for dynamic animation and stylish action sequences.
Motonobu Hori (Carole & Tuesday) is directing, with Kimiko Ueno (Delicious in Dungeon) handling series composition and scripts, and Kōhei Tokuoka (The Fragrant Flower Blooms with Dignity) designing the characters.
Composers Taisei Iwasaki and Yuma Yamaguchi are slated to provide the music for the show.
MARRIAGETOXIN cast highlights
Fans can also expect a strong voice cast bringing MARRIAGETOXIN’s eclectic characters to life.
The leads are Haruki Ishiya (Ido in Scum of the Brave) as Gero and Shion Wakayama (Momo in Dandadan) as Mei.
They are supported by a roster of additional talent like Hinano Shirahama (who plays Kimie), Souma Saitou (Genya), Asaki Yuikawa (Shiori) and Anna Nagase (Kyouko) portraying characters who range from fierce fighters to colorful allies and rivals.
Now officially slotting into the Spring 2026 anime season, MARRIAGETOXIN joins a robust lineup of new and returning series.
Its April 7th premiere marks the start of what many fans hope will be a fresh and funny hit, combining intense action with character-driven romance and comedy.
With its blend of genres, stylish production, and a quirky premise that turns classic matchmaking tropes on their head, MARRIAGETOXIN is shaping up to be one of the standout entries of the season. I can’t wait. How about you?
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