This is the one that shows up glued to a special-edition CoroCoro, which is exactly the right delivery system for Grandpa Danger. Eight years after the TV shorts, the old man is still the world's great protector, still an expert at falling off cliffs, still weaponizing phlegm and farts at a volume no reasonable person would permit. Grandson is still the load-bearing straight man, and the principal with the inferiority complex is still a walking punchline waiting to be kicked. Nothing about this franchise has ever tried to be more than a gag manga screaming at a grade-schooler's funny bone, and that refusal is the whole appeal. One episode, no arc, no lesson, just the specific joy of buying a magazine for a kid and finding a disc taped to it.

Dangerous Jii-san Ja is a one-episode comedy OVA released in 2012, distributed alongside a special printing of the manga magazine Coro Coro Comics. Grandpa Danger comes from the Dangerous Jiisan franchise, whose earlier TV series cast him as a crude, relentless prankster. In those shows his phlegm and farts pushed his grandson to comic extremes of frustration.