Housekishou Richard-shi no Nazo Kantei S01E10 - The Lapis Lazuli of Guidance

Working off of the hint Richard left for him, Seigi heads to the lapis lazuli exhibit at the British Museum. There he finds Richard disguised as a woman. While carefully watching their surroundings, Seigi and Richard flee from the scene. Richard attempts to send Seigi back to Japan, but Seigi refuses to leave until they talk, and the two disagree. When the past Richard had kept secret is revealed, how will they choose to act.