Plusle and Minun

Rayo: He's the natural leader of the two (even though they're the same size). Brave, hyperactive, and incredibly curious. He's always the first to get into trouble: he knocks things over with his tail, tries to "energize" the refrigerator to make it colder (and leaves it practically glowing hot), and when he sees me coming, he runs towards me yelling "Plus! Plusleee!" and jumps up my leg, releasing static electricity that makes my fur stand on end. He's super affectionate, but also bossy: if I don't pay attention to him, he cries dramatically until I pick him up. He loves to clap his paws when something goes well (or when he thinks it went well).
Sparkle: The shy and protective little sister. She's quieter, but if Lightning gets into trouble, she follows behind, releasing blue sparks of concern. She loves to snuggle up to my neck or scarf, and when she sleeps, she releases little waves of soothing electricity (like a warm massage). She's the first to notice if I'm sad: she gets serious, touches my cheek with her blue paw, and starts releasing soft sparks as if to say, "It's okay, I'm here." When she plays with Lightning, she always ends up being the one to calm him down after he gets carried away.
The two complement each other perfectly: Lightning McQueen animates and creates chaos, Sparky supports him and cleans up the mess with her calmer electricity. When they sleep, they hug tail to tail (the + and the − together) and emit a cute little buzz like an electric purr.

Spark (Minun):
Just as creamy and fluffy, but its ears are vibrant sky blue, its cheeks have a white symbol with a blue border. Its little paws are blue, and its tail has a symbol that it waves like a flag. Its eyes are just as big, but it has a shyer, sweeter expression, as if it's always asking permission for everything. When it gets excited, it releases tiny blue sparkles that look like little fireworks.

Appearance (ultra-cute baby version)
They're even smaller than the regular Plusle and Minun, about 20-25 cm tall when standing, with chubby, soft bodies like newly made plush toys. Their ears are big and droopy from being abandoned, but when they get excited, they stand up stiffly and start to vibrate.
Rayo (Plusle):
His fur is incredibly soft and creamy, almost white from how clean he was after his bath. He has long, bright red ears, round cheeks with a white plus sign in the center and a bright red border. His paws are short and red, and his tail has a plus sign at the end that he wags like a cheerleader's pom-pom. He has huge, sparkly black eyes, and he always seems to be smiling mischievously. When he's happy, he releases tiny red sparkles that form little hearts or plus signs in the air.

Two bipedal, mouse-like Pokémon. They don't usually speak.

The Plusle (the one with the ears and red markings +) → Rayo
The Minun (the one with the blue ears and markings −) → Spark