"Monster…!!" (怪物…!!, Bakemono…!!, Viz: Monsters!!) is chapter 31 of the Boruto manga.
At Naruto's request, Kawaki confirms Delta's identity as an Inner from Kara. Delta is aware of who Naruto is, and asks him to stand aside so she can deal with Kawaki. Kawaki warns Naruto that all Inners are monsters. Boruto notices Kawaki's change of attitude as a sign of how dangerous they are. Naruto refuses to hand Kawaki over, and Delta decides to kill Naruto. Naruto tells Boruto to protect Himawari, and Kawaki to defend himself. Delta strikes first, trying to kick Naruto, but he dodges her attacks, grabs her by the leg, and slams her on the ground. Naruto uses a Rasengan against her, but Delta absorbs it with her Shinobi-Ware eye. She attacks Naruto from below by transforming her leg in a way similar to Kawaki's body transformations, but Naruto dodges it as well. Delta confirms she has been extensively modified with scientific ninja tools. She attacks Naruto again, who activates his chakra mode. Naruto blocks her kick, but Delta transforms her leg upon impact, causing it to grow spikes, one of which pierces Naruto. Naruto creates chakra arms crushes Delta's leg, causing her to retreat while considering him to be a monster himself. Delta's leg regenerates, and she taunts Naruto's performance. Boruto tries intervening, but Naruto warns him to stay back. Delta is indifferent, content with killing them both. Naruto threatens Delta, who kicks him and steps on him. Delta reiterates she's only interested in Kawaki. Delta is baffled by Naruto's commitment to stranger who brought him only trouble, and Naruto is likewise interested in how desperate she must be to come alone into enemy territory. Delta questions his curiosity considering his situation, and Naruto admits being worried is in his nature. Delta twists the spike on Naruto's abdomen, removes it, and admonishes him for his attempt at deceit while his wound heals. Naruto admits to trying to get intel from her while pretending to be weakened. Angry at the deception, Delta activates a chakra cloak of her own, promising to tear Naruto apart. Naruto warns the kids to get further away, and begins trading blows with Delta again. When the two are locked in place, Delta releases the Rasengan she absorbed before back at Naruto, who dodges it. Boruto watches in awe.
- The chapter's title would normally be read as "Kaibutsu…!!", but the furigana gives its reading as "Bakemono…!!" instead.