@lupus_in_fabula
The badum badoom is supposed to be the train noise. But Robo was making the noise the whole time. Also, o-of course I b-bought this manga...
@tanukihat "Dodes Kaden" is, actually, a train (precisely a trolley car) noise made by one of the characters of the movie, supposed to be mentally challenged. That's why I asked. I don't khow if you literally translated the onomatopoeia (and then it sounded Badoom Badoom in japanese too) or adapted it.
Let's get this straight: I'm not doing it to be a smug know-it-all. If this can be of use to improve your translation, I will be happy to be of help.