Sui is the slime that Mukouda picked up as a familiar, mainly because it was adorable and turned out to be surprisingly useful around the camp—especially when dealing with trash and debris from the other world. It travels with Mukouda and Fel inside Mukouda's bag as a constant companion.
Everyone assumed Sui was just a regular water slime at first, but Mukouda's cooking changed everything. The food he made gave Sui ridiculous stat boosts that unlocked hidden abilities: it learned magic, developed the ability to speak, and became capable of producing high-grade medicine. The power creep was real.
Personality-wise, Sui is basically always excited about something. It's incredibly supportive and genuinely positive, whether that means helping the party out or going toe-to-toe with powerful monsters. Fans often note that Sui shows affection by creating a heart-shaped symbol inside its translucent body when it really likes something—which happens a lot around Mukouda's cooking.
Content compiled by AnimeList.moe from publicly available sources.
