Nothing in particular seems to really happen in each episode of Usagi Drop, but then you look back and realize the kids are growing up so quickly.
We get introduced to Kouki and his single MILF of a mother in this episode. Unlike Rin, Kouki’s a bratty boy with poor manners, which results in Rin taking an amusingly motherly role with him (something we’ve seen her do to Daikichi as well. Pft, boys will always be boys).
While Kouki lives out the cute childhood friend fantasy that’s so prevalent in anime, Daikichi runs into Kouki’s pretty, and divorced mother during one of his late night pick-ups of Rin. The two instantly bond in the same way Rin and Kouki have bonded. Like Daikichi, Kouki’s mom finds herself in the unenviable position of being a single parent. Unlike Daikichi though, who basically won the lottery of cute and responsible children, Kouki’s mom is stuck with a whiny, unappreciative little brat, as little boys often are. However, meeting Kouki’s mom, gives Daikichi the impression that it would be good to have a mother in Rin’s life, and deepens his conundrum of trying to find more info about Rin’s mother, Masako.
Some sleuthing leads Daikichi to his grandfather’s hidden will, which reveals for certain that his maid was indeed Rin’s mother, but also reveals his thoughts about her – that she wasn’t a bad person, but perhaps unfit to be a mother – in addition to her contact info. This leads Daikichi to wonder about what circumstances could have led her to leave Rin with the family. And whether those circumstances have changed enough where she’d want to take Rin back. But would that be the best for Rin? To go back to a mother who once abandoned her? No matter how much she could have changed, nobody fit to be a mother would just leave her child like she did, could she?
Adding to Daikichi’s internal struggle is Daikichi’s growing bond with Rin. Life may be different for Daikichi now. But it’s not worse. Is it better? Is life better with Rin in his life? There’s some great moments in the show where you see the bond with each other. From obvious ones like Daikichi doing Rin’s hair, or carrying her across the street, to more subtle ones like Rin holding onto Daikichi when the two arrive at the goodbye party, only to be greeted by a group of drunkards. I don’t know if the relationship is exactly father-daughter, but perhaps something a bit more casual, a bit more familial. Like a mix between big brother and father. As Rin says, “Daikichi is Daikichi” … “and my dad is my granddad”… “and my sister is my caretaker’s mother.” Yep.