Kaku previously worked as an assistant to Tatsuki Fujimoto, the creator of Fire Punch and Chainsaw Man, and also worked as an editor at Shueisha. In 2009, Kaku made his debut after working on his 41-page oneshot, The Remembrance Tax (おもいで税関 Omoide Zeikan?), which earned the 14th honorable mention of Jump SQ.'s Newcomer Cartoon Award "Supreme Comic Grand Prize." The manga was later published in Jump SQ.II and was included in Jump SQ. Comic Selection 2 in 2010.
In 2013, Kaku published his second work Fantasma (ファンタズマ Fantazuma?), originally named BAD☆SWING, as a oneshot in Jump SQ Issue 2012-07. Around a year later, the manga was turned into a series and started in Issue 2013-08 of Jump SQ. The last volume was released on July 4, 2014.
In 2016, Kaku created a new oneshot, Jailbreak Princess (脱獄姫 Datsugoku Hime?) and had serialized in Jump SQ. Crown.
In 2017, Kaku presented the storyboards for the first three chapters of his next manga, Hell's Paradise: Jigokuraku (地獄楽 Jigokuraku?), to the Shōnen Jump+ editorial staff. Having become a big fan of Kaku's art since Fantasma, Hideaki Sakakibara enthusiastically volunteered to take on the series and became the manga's second editor with chapters two and three. He believed that Jigokuraku was the "mainstream battle fantasy" series that Jump Plus was still lacking and could become a best-seller in print. As he helped work on the series, Sakakibara credited Kaku's genius at quickly and simply introducing characters and his drawing talent for making it all work.
Kaku and Sakakibara worked together by planning out what was going to happen in sets of 10 chapters, or a whole volume. The editor gave Kaku free reign as far as illustrations were concerned. Sakakibara said that from the first chapter the series has had "extreme" illustrations, which has resulted in popularity among readers, but makes it hard for new readers to get into. Kaku and Sakakibara said that they were currently trying to earn more female readers. According to Sakakibara, he said it was easy to communicate things to Kaku since he was a former manga editor, as the artist was quick to figure out what he meant. However, Kaku admitted that this had caused him to unconsciously hold back creatively by thinking objectively like an editor.
- The Remembrance Tax (おもいで税関 Omoide Zeikan?) - Published in Jump SQ.II and Jump SQ. Comic Selection 2 in 2010.
- Jailbreak Princess (脱獄姫 Datsugoku Hime?) - Published in Jump SQ. Crown in 2016.