Sanriocore

Sanriocore is an aesthetic centered around Sanrio Co., Ltd.(株式会社サンリオ) a Japanese company created by Shintaro Tsuji that sells cute (or Kawaii) Japanese merchandise. Sanrio's most popular icon, Hello Kitty, has become one of the world's best-selling brands. Sanriocore focuses on the more popular Sanrio characters such as:

Hello Kitty
My Melody
Gudetama
Badtz-Maru
Pekkle
Wish me mell
Shirousa
Kurousa
Kuromi, etc.
Cinnamoroll squad

Visual

Sanriocore crosses over into multiple aesthetics such as Traumacore (the aesthetic can be used as a form of vent art in this case) but is closely related to Kidcore and Softie. It focuses on a gentle, childlike innocence and nature, accompanied by the cute Sanrio merch and characters.

However, there are multiple sides. The most common is goth Sanrio, mostly centered around the characters Kuromi, hello kitty, and my melody. It's a little less soft, and a bit more grungy. Pink and soft colors are still used, however, they are often paired with:

Black clothing, mostly oversized hoodies
Small skirts that the hoodies tend to cover
Platform demonias
Fishnets
Legwarmers
Spiked collars
Masks
Maid outfits/dresses
Black cat ears
Black nail polish

Fashion & Makeup

Sanriocore fashion pulls some elements from Pastel Goth, Yanderecore, Softie, and Larme Kei. Some fashion in this aesthetic can include:

Babydoll dresses
Lolita dresses
Hoodies/shirts with sanrio motifs
Pastel skirts
Band-aids with sanrio motifs
Barrettes
Sanrio merch (eg. backpacks, toys and keyrings)
Mary janes, chunky boots, heels, chunky sneakers or oxfords
Fishnets
Knee, below the knee, or thigh-high socks
Baby-ish pastel blouses

Neutral looks with heavy blush can be seen, as well as pink, glittery eyeshadow with fake lashes. Pink lips or lip gloss with/without glitter seem popular as well. Nails tend to have heavy Sanrio deco.