Quoting pages 77–78 of Louise Young’s Japan’s Total Empire:

The sensationalizing of the “three human bombs” (or bullets), the [Imperial] soldiers who were blown up in the line of duty during the [1931] assault on Shanghai, cast all other new heroes into shadow. The [Imperial] army publicized the three deaths as a conscious act of suicide, claiming [that] the young men had sacrificed themselves to explode a section of wire fence impeding the army’s advance. […]

Throughout March, “three human bullets” productions swept the entertainment world. […] No fewer than six movie versions were produced in March alone, and at vaudeville reviews at places like the Horie Dance Hall, the chorus line kicked their heels to the “Three Human Bullets Song.” Record companies brought out a string of “human bombs” songs, which were multiplying due to song contests in […] newspapers and magazines. […] Before long, even “human bullets” products appeared on the market. Entrepreneurs from the dead men’s home towns began selling “three human bullets saké” and “three human bullets bean paste candy,” and an Osaka department store dining room showed questionable taste in offering a “three human bombs” special: radish strips cut to simulate the explosives tube and butterburs representing the “human bombs.”

(Emphasis added.)