-Miku, Rin, and Len are all best friends since Miku was the only teenager around before the twins were released

-Miku and Rin have that thing with teenage relationships where they're crushing hard on each other and they're sorta dating but also not really. Len ships them hard

-Meiko, Kaito, and Luka are polyam goals. Basically Meiko and Kaito were together, then Luka was released and they were both like "Yo she's low-key kinda cute tho 😳"

-Miku and Luka are sorta honorary siblings. They play-fight a lot but they love each other

-Miku and Teto used to be rivals but now they're besties

-Miku, Neru, and Haku are cousins

-Teto and Neru are Miku's other best friends

-Sweet Ann and Big Al are married and Oliver is their son

-Piko and Miki are twins, but they had no idea for a long time due to the whole being sold to different companies thing

-Fukase, Flower, Piko, and Oliver are all friends obviously

-Hime and Mikoto are Flower's found family little siblings

-Iroha, SeeU, and Mew are cat besties

-Teto and IA have a "forbidden" relationship, since IA's a Vocaloid and Teto's an Utau. Miku and Neru are the only ones who know.