Ojiichan wa Shounen Tanteiおじいちゃんは少年探偵 ; Grampa is a Boy Detective ; Ojii-chan is a shonen detective? ; Ojii-chan wa Shounen Tantei ; 我的爷爷是少年侦探

Basically, the teenage detective kiddo was frozen by some EVIL MASTERMIND PROFESSOR back in near-mid-1900’s, and gets unfrozen in the 2000’s by his granddaughter. Hilarity ensues as he encounters weird new stuff and does silly blunders in his daily life with his granddaughter, Hikari.