Tanjirou punches the boar-man to get him off Zenitsu, breaking his ribs in the process while scolding him for raising his sword(s) to a fellow Demon Slayer. The boar-man, named Hashibira Inosuke, decides to fight Tanjirou hand-to-hand (and foot-to-foot).
As both have cracked ribs, they fight on more or less an equal level. Inosuke has an advantage in flexibility and how damn low he can get (Tanjirou likens it to fighting a four-legged beast). Tanjirou isn’t really trying to fight, but when Inosuke won’t let up, he deploys his secret-weapon: his titanium-hard skull.
The headbutt is devastating enough to knock Inosuke’s boar mask off, revealing a beautiful, feminine face that seriously freaks out Zenitsu (though to be honest everything freaks the guy out). Inosuke passes out, then wakes up to find the others burying bodies from the mansion.
When he says he won’t help, Tanjirou chalks it up to Inosuke’s wounds hurting too much, only angering the boar-man more. A Kasugai crow arrives, gives the three rescued siblings a wisteria charm so they can return home safely, and leads the three slayers to a manor with a Wisteria crest at the gate, ordering them to rest there until fully recovered.
A comedy triad ensues at the inn-like manor, whose owners were saved by Demon Slayers and thus allow them to stay there free of charge. Tanjirou is glad for the change of clothes, food, and bedding, and even Zenitsu mostly calms down, but Inosuke is constantly trying to pick a fresh fight with Tanjirou.
Fortunately our laid-back protagonist doesn’t rise to the provocations, preferring to rest up so that he can more effectively fight the real enemy: demons. When the three lay down for the night, Inosuke tells the others how he, an orphan with no family, stole a Nichirin blade from a Demon Slayer who “trespassed” on “his mountain”, then heard about the Final Selection and basically thought it’d be cool to do that.
Zenitsu steers the conversation to the box Tanjirou has been carrying, and asks him straight up why he travels with a demon. Tanjirou thanks Zenitsu for protecting it even though he knew of its contents, and the praise goes straight to Zenitsu’s head (though he vehemently denies he’s strong). Before Tanjirou can tell him that the demon is his sister, Nezuko starts scratching at the door of her box, scaring the shit out of Zenitsu.
She crawls out and grows to her normal size. Once Zenitsu gets a good look at her, he draws his sword on Tanjirou for keeping such a “cute girl” in a box and not telling anyone, and threatens to “purge” him. Meanwhile, Inosuke can’t remember why he first picked a fight, and falls asleep instantly, missing the big Nezuko reveal. This was probably the most laid back and fun episode of Demon Slayer to date, a well-timed breather from all the recent demon battles.