Watch the uncredited opening and ending of Mission: Yozakura Family here

The animation is from the studio SilverLink (The Misfit of Demon King Academy, Boufuri, Ange Vierge, Dusk maiden of Amnesia), directed by Mirai Minato (Fate/kaleid liner Prisma Illya, Our Last Crusade or the Rise of a New World, BOFURI: I Don’t Want to Get Hurt, so I’ll Max Out My Defense.), the character designs are by Mizuki Takahashi (Mushoku Tensei: Jobless Reincarnation) and the song was given to Koji Fujimoto (Ragna Crimson, Tearmoon Empire) and Osamu Sasaki (The Great Jahy Will Not Be Defeated!, Ragna Crimson).

In the description of Mission: Yozakura Family we can read:

High school student Taiyou Asano has been socially inept since his family was killed in a car accident. The only person he can properly relate to is his childhood friend, Mutsumi Yozakura, the head of the strongest spy family in the world. Mutsumi’s older brother, Kyouichirou Yozakura, has been overprotective of her since she was seriously injured. His love for Mutsumi is lethal, and Taiyou is her next target. To survive, Taiyou must marry Mutsumi and become a member of the Yozakura family. Thrown headlong into chaos, Taiyou begins his journey to become a powerful spy to protect his wife and uncover the dark secrets of his and the Yozakura family’s past.