TOKYO — Tsuburaya, the producer of the iconic “Ultraman” sci-fi series, is being acquired by pinball and slot machine-maker Fields Corp.

Fields is acquiring a 51% stake from Tsuburaya parent TYO, whose core biz is TV commercial production. Toymaker Bandai will retain its 49% share.

The value of the deal was not revealed on Wednesday, but Fields plans to complete the acquisition in early April. TYO acquired Tsuburaya in 2007.

Fields plans to use “Ultraman” characters — especially popular with Japanese boomers — on their machines, which are used for legalized gambling. Also, in cooperation with Bandai, the company intends to develop character goods from any new “Ultraman” series.

Founded in 1963 by pioneering effects maestro Eiji Tsuburaya, Tsuburaya was instrumental in popularizing tokusatsu — live-action, special effects-driven TV shows featuring a super hero.

The “Ultraman” series, whose heroes are giant spandex-suited aliens who battle space monsters on Earth’s behalf, has spawned not only a long-running show but movies, videos and character goods.