Yuuki Kagurazaka

Yuuki Kagurazaka is a key supporting character (and later antagonist) in the anime adaptation of That Time I Got Reincarnated as a Slime (Tensei Shitara Slime Datta Ken). He is a fellow Japanese otherworlder like Rimuru and Shizue, summoned to the fantasy world as a teenager/young man.

In the anime, Yuuki first appears prominently in Season 1 (around the episode titled after him) as the Grand Master of the Free Guild (Freedom Association), the organization that manages adventurers worldwide. He runs the guild branch in Ingracia and also serves as the principal of the Freedom Academy, where Shizue Izawa once taught children (including the ones Rimuru meets to fulfill Shizue's last wish).

Yuuki comes across as friendly, intelligent, laid-back, and somewhat otaku-like—he gets excited about manga and modern Japanese references when Rimuru shares them. He helps Rimuru get an adventurer card and seems cooperative at first, sharing a connection through Shizue (who was his former teacher). Voiced by Natsuki Hanae (Japanese) and Clifford Chapin (English), he has a youthful, charismatic vibe with short dark hair and sharp features.

As the story progresses into Season 2 and beyond, his role becomes more complex and antagonistic. He leads (or co-leads) the Moderate Harlequin Alliance (a group of eccentric, powerful subordinates like the clown-like members) and gets involved in larger schemes that put him at odds with Rimuru and others, often manipulating events from behind the scenes for his own ambitious goals related to reshaping the world.

The anime sticks closely to the light novel's portrayal of Yuuki (more nuanced and layered than some early web novel versions), showing him as a cunning, genius-level strategist with hidden depths rather than a straightforward villain from the start.