Can anyone recommend some manga that could introduce you and get you interested in other activities? Examples that I could think of off the top of my head would be Eyeshield 21 and football, Ballroom e Youkoso and ballroom dancing, or even Slam Dunk and basketball.
Gunsmith cats and guns
irl spoiler: chicks don't actually go to the range
"Hikaru no Go", it even inspired a Linux distribution dedicated to the game of Go (Hikarunix).
I just remembered Captain Tsubasa, a classic.
Akagi and mahjong
Saki and mahjong
Ace of Diamond and baseball
Lots of sports stuff is like this so it's kind of a given, let's see if I can think of something more nonstandard...
Kantai Collection and Arpeggio got me more interested in learning about the Imperial Japanese Navy.
GATE made me want to know more about the JSDF. Probably some not so subtle propaganda there, but I like it.
Kingdom and Chinese history... this is kind of a dead end because the Emperor from that time period was kind of a douche and burned all the books. Still damn good though.
So yeah, lotsa stuff out there that fits what you're looking for. That only scratches the surface but that should be more than enough to get you started.