The 55th chapter of Monster Musume: Everyday Life with Monster Girls. With Suu once again turned into Super Suu, her fight with her evil counterpart finally reaches its conclusion.
As Nega-Suu and Super Suu, the latter carrying Kimihito between her breasts, stare each other down, Miia and Centorea can only stare in amazement about the sudden turn of events. Mr President realizes that the high nutrition in the royal jelly must have caused Suu's rapid growth, though he admits that even he is surprised by the effects. Miia comments that Suu now has a chance to defeat Nega-Suu.
Suu starts the fight by launching a massive beam of highly-pressurized water from her mouth, which decapitates Nega-Suu, much to Miia and Cerea's amazement. As the latter two start to comment on the turn of events, Smith calls them out on this, only for Miia to respond that they're in no danger since Suu has already won. However, Mr President realizes that the fight is not yet over, as Nega-Suu regrows her head. Mr President explains that as long as a Slime's core is intact, they can keep regenerating indefinetly. Suu, realizing this as well, grabs a specialized vacuum device with one of her tentacles and gives it to Kimihito, telling him to use it to suck up Nega-Suu's core once he finds it.
Now both Slimes fire a beam at each other, and the water beams collide mid-air. Cerea comments that the two giant Slimes are equally matched, and that whoever finds an opening first would win. As she says this, Nega-Suu grabs one of the tankers filled with the absorbing polymer and throws it at Suu. Covered with the chemicals, Suu is immobilized, though stops panicking once she notices Rachnera's threads subtly hanging nearby. Nega-Suu then launches her tentacles at Suu, which causes Kimihito to be launched into the air and straight into Nega-Suu's body. Smith and Mr President panick, realizing that Nega-Suu's body will start to digest him. However, as Nega-Suu does this, it is quickly revealed that the Kimihito inside of her is in fact a dummy made by Rachnera, and covered with some of Suu's slime.
Rachnera explains that the polymer is not going to do much to Nega-Suu as long as her core is protected, and thus they need to attack her from the inside. As Mr President catches on, Rachnera cuts one of her threads, and the dummy unravels itself, revealing it to be filled with the absorbing polymer. The chemical quickly proceeds to eat through most of Nega-Suu's body, finally exposing her core. Seeing her opening, Suu opens her mouth and spits out Kimihito at Nega-Suu. Kimihito successfully vacuums up Nega-Suu's core, rendering her powerless.
Before they can celebrate, however, Kimihito starts to sink into Nega-Suu's immobile body, and Mr President realizes that the Slime that constitutes Nega-Suu is reverting back to a conventional liquid. As Kimhito fully submerges into the slime, Suu tries to grab him out, only to find her hands dissolving upon contact with the still-corrosive slime. Seeing her master in danger, and being out of options, Suu dives fully into the slime. While Kimihito starts to suffocated and feel the slime burning his skin, he suddenly finds himself surounded by Suu's essence. Suu has formed a bubble of her own body around him, but now Suu is starting to dissolve instead.
Kimihto starts to panick, but Suu reassures him that she's fine as long as he's okay, and Kimihito blacks out just as Suu's essence starts to fully dissipate. Awakening outside of Nega-Suu, Kimihito finds himself surrounded by Miia, Cerea, and Smith. While they are elated that Kimihito survivived, they realize what Suu did to save him. Before they can mourn, however, Kimihito starts coughing heavily. As they wonder what's wrong with him, he vomits up a small sphere. The sphere turns out to be Suu's own core, who assures them she's alive. Kimihito explains that, moments before he lost consciousness, he saw Suu's core and quickly swallowed it to keep it safe.
As everybody congratulates him, Mr President turns towards Rachnera, who scolds him for sending those other Liminals towards them in the first place. He explains that he did it because he considers Rachnera worth the trouble. A flashback reveals that when Rachnera had turned against Kasegi and tied him up, she used his phone to call Mr President, who turns out to be Kasegi's brother. Mr President reminisces about Rachnera blackmailing him with his brother's illegal activities, and was greatly impressed by it. As Rachnera wonders what he tries to do, Mr President offers her to work for him.
- Nega-Suu is defeated and her core captured.
- In the process, most of Suu's body was dissolved and she was reduced to just her own core.
- Mr President is revealed to be Kasegi's younger brother.
- Mr President once again offers Rachnera to work for him.