Zettai Zetsumei Dangerous Jiisan (2005)

Dangerous Grandpa is still convinced that survival depends on following his uniquely terrible advice, and his grandson is still the unfortunate person forced to witness every demonstration. Ordinary problems become disasters the moment Grandpa decides he has discovered the perfect solution.

School, home, games, and neighborhood life all become stages for impossible inventions, reckless lessons, and jokes that ignore common sense. The only reliable rule is that Grandpa's attempt to prevent danger will probably create much more of it.