After graduating in the early 1980s, Mochizuki briefly worked at the Nikkatsu studio which was exclusively producing its Roman porno line of films at that time.
Mochizuki had been encouraged to write scripts by one of his teachers at Image Forum and in 1983, one of his screenplays was made into the pink film Virgin Rope Doll by Genji Nakamura for his Yū Pro company.
[2][3] He continued working with Nakamura as a screenwriter and assistant director, including writing two gay-themed pink films, Beautiful Mystery (a parody of Yukio Mishima's right-wing activities[4]) and Our Season (a.k.a.
[15] He also returned to his erotic film roots with his 2000 movie, Currency and Blonde, about a Japanese university lecturer and his sadomasochistic affair with his American lover.
His treatment, with hip-hop singer Shinya Taniuchi, who played the titular character, and actress Jun Fubuki, has been criticized as being superficial and romanticized.
[2][13] After the loss of his production company and the cancellation of other projects, Mochizuki returned to directing adult videos as well,[2] with works in the 2000s for Alice Japan and Max-A, some featuring AV idols Milk Ichigo, Ryōko Mitake and Akiho Yoshizawa.
[17] Mochizuki's 2005 film for the Toei Company studio, Wet Red Thread concerned two former prostitutes played by Saki Takaoka and Rei Yoshii looking to start a new life.
In Mochizuki's version, a young photographer becomes obsessed with the married Sada (played by actress-dancer-singer Aya Sugimoto) and his affair with her brings back memories of a former life together with her.