Fate/Grand Order: Fujimaru Ritsuka wa Wakaranai

Ritsuka Fujimaru may be humanity's last Master and one of Chaldea's most important people, but his greatest weakness is surprisingly ordinary: he asks every question that crosses his mind with complete sincerity.

Whether the subject is a Heroic Spirit's habits, a strange rule of magecraft, or something everyone else thought was obvious, Ritsuka's innocent curiosity repeatedly leaves Servants scrambling for an answer. Saving humanity is serious work, but life in Chaldea rarely stays serious for long.