TOKYO — In almost every way, Akihiko Kondo is an ordinary Japanese man. He’s pleasant and easy to talk to. He has friends and a steady job and wears a suit and tie to work.

There’s just one exception: Mr. Kondo is married to a fictional character.

His beloved, Hatsune Miku, is a turquoise-haired, computer-synthesized pop singer who has toured with Lady Gaga and starred in video games. After a decade-long relationship, one that Mr. Kondo says pulled him out of a deep depression, he held a small, unofficial wedding ceremony in Tokyo in 2018. Miku, in the form of a plush doll, wore white, and he was in a matching tuxedo.

In Miku, Mr. Kondo has found love, inspiration and solace, he says. He and his assortment of Miku dolls eat, sleep and watch movies together. Sometimes, they sneak off on romantic getaways, posting photos on Instagram.

Mr. Kondo, 38, knows that people think it’s strange, even harmful. He knows that some — possibly those reading this article — hope he’ll grow out of it. And, yes, he knows that Miku isn’t real. But his feelings for her are, he says.