Chess
When I first met Shikarmaru, it was because he and I were put together in for strategy planning. Apparently everyone thought that I knew everything. So I gave whatever input I could.
After the meeting, Shikamaru asked to play shogi with me. I taught him how to play chess instead. After the game, he murmured, "no wonder you had such different opinions…"
I rolled my eyes but secretly chucked in my mind. This kid really analyzed everything, didn't he?