Ojiichan wa Shounen Tantei - 35 chapter(s)
Feb-25-2018
Basically, the teenage detective kiddo was frozen by some EVIL MASTERMIND PROFESSOR back in near-mid-1900s, and gets unfrozen in the 2000s by his granddaughter. Hilarity ensues as he encounters weird new stuff and does silly blunders in his daily life with his granddaughter, Hikari.