Watch Tensei Shitara Slime Datta Ken episode 21 online
Rimuru becomes the new teacher for Shizu`s students. However, having been summoned into this world against their will and facing shortened lifespans as a result, the children`s feelings are complicated, and they`re reluctant to accept Rimuru. So Rimuru proposes a series of mock battles with each of them to ascertain their abilities and allow them to let off steam.
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