✶ Since Hisoka is versed in traditional medicine, Rin ends up going to him whenever he needs a cut or any other wound patched up. He'd prefer to not show his body and is rather embarrassed to do so, but it's either that or taking longer to heal (potentially jeopardizing his career as a hockey player, which would be unacceptable). They sit together in silence while Hisoka treats him; it's an awkward thing, at first, because Rin's social persona gets mixed with insecurity over exposing his scars to someone he's not even particularly close to, leading him to blabber while Hisoka's not very interested in conversation (and certainly thinks he's annoying). As this situation repeats, they eventually fall into more comfortable silences, growing used to each other's presence.
✶ Being very curious (and nosy!), Atsuko is fascinated by Mizuki's lavish presence and life experiences abroad. While Mizuki looks down on those poorer than she is, Atsuko doesn't seem like the type to back down and bottle her feelings when she feels wronged. This is not a good match to Mizuki's tendency to snap, at first, and it leads to some terribly petty arguments until one of these confrontations forces her to consider Atsuko's point of view for the first time. Such a turn of events makes Mizuki start thinking of Atsuko's natural curiosity and dedication to mysteries as an endearing trait, and they eventually develop a calmer bond.
✶ Mizuki and Atsuko often practice different languages together as they grow closer. Mizuki is a very strict teacher when it comes to French, making sure Atsuko's accent isn't crassly wrong, and Atsuko teaches her Japanese Sign Language in return. Having these additional shared forms of conversation is also very handy whenever they're in a room with other people and want to communicate without being understood by everyone else; it's a special little thing of their own.
Giuseppe & Lavinia (familial) | Klaus/Nebi (romantic. these two are ANGSTY but absolutely made for each other) | Jürgen & Nadin (platonic, they're besties) | Massimo/Fabrizia (romantic. he's a bit of a douche /rip)