Expy: Of sorts to Doraemon, as pointed by various references through the series. She comes from the future to prevent Sakura from turning out bad much like how Doraemon did for Nobita, but for twistedly nonsensical reasons.
Genki Girl: This girl is incredibly energetic even when the chips are down.
Girlish Pigtails: She sports a pair of these, which help add to her cute design.
Death Seeker: Played for comedic effect. It is implied that one of the reasons why he always acts so Too Dumb to Live around Sabato by constantly offerring to help her or falling for her seduction despite the fact that she is on a mission to actually kill him for good is that he wants her to succeed so he doesn't have to deal with Dokuro's constantly killing and resurrecting him.
The Dulcinea Effect: He's always willing to help Sabato, despite how often she's tried to kill him.
Nice Guy: Grows fond of Dokuro despite how she treats him, and brings food to the homeless Sabato when she's not looking, since she's not a bad person either and he feels sorry about her having to be stuck in the past unless she could kill him.
Ill Girl: Frequently, particularly in season two. It's mostly just a cold, but it's exacerbated by her less-than-ideal living conditions. Like just about everything else in this show, though, this is Played for Laughs.
Everyone Has Standards: When Sakura tells Shizuki about how he doesn't want Zakuro to take Dokuro back to the future, Shizuki quickly reminds him that Dokuro has done nothing but cause him pain and trouble since her arrival.