Operation: Mystery·NHK
All episodes
4 seasons · 34 eps
Season 4
S4 · E1
45 min
S4 · E1
45 min
S4 · E2
45 min
S4 · E2
45 min
地を這う女王 Episode 2
S4 · E3
45 min
S4 · E3
45 min
闇に蠢く美少女 Episode 3
S4 · E4
45 min
S4 · E4
45 min
深淵を覗く者 Episode 4
4 episodes in Season 4
Some details come from TheTVDB.