Still the Sonic main canon series are from and was created in Japan in the first place.

Japanese culture appeal examples
1. The anthropomorphic animals' Modern designs have a more anime-oriented style, resemble to some classic japanese/anime characters, Chibi-like anime characters/dolls/figures and Meowth from Pokémon.

2. Most the anthropomorphic animals' Modern designs' eyes similar to some classic japanese/anime characters' eyes like some 1-3 generation Pokémon, some 1-3 generation Pokémon human characters, some Mega Man characters, some Keroro human characters, some Bakusō Kyōdai Let's & Go!! human characters, Pete from the first Harvest Moom gameboy game and Atsuko Kagari from Little Witch Academia.

3. Amy, Cream and Vanilla's clothes are similar to some Lolita fashion, some of Amy's clothes similar to some Chibi-like anime girl dolls like both some Pretty Cure playset dolls' clothes and Ojamajo Doremi bootleg keychains and figurines' cloths, Amy's dress similar to both Roll's original dress and some of Ms. Mari's dresses from one of her concept arts from Mega Man, Yorin/Yorang's dress from Hey Yo Yorang, The Powerpuff Girls Z's dresses and the Ojamajo Doremi in nurse outfits bootleg keychains and figurines' nurse dresses and Cream's dress similar to both two of the Sonic Adventure young human girl NPCs and Molly Hale's dress as 10 year old from Pokémon.

4. Some random Modern Sonic characters like the humans from both the game Sonic Adventure and the anime Sonic X, Maria Robotnik in Sonic Channel website artworks, the Chao creatures and human-like characters like Shahra, Merlina the Wizard, Sage, Lah and females of Cosmo's species/female Seedrians' designs have a more anime-oriented style as well.

5. Sonic, Shadow and Silver as hedgehogs has quills as anime spikey hairstyles, Tails has hair antennae/ahoge anime hair and Amy's hair bangs similar to Pete's hair bangs from Harvest Moon.

6. Tails is a fox with more than one tail as Kitsune from japanese folklore.

7. Amy's Piko Piko Hammer weapon is based on the popular japanese children's toy of the same name.

8. Rouge resemble to some sexy japanese/anime demon girls like Morrigan from Darkstalkers.

9. Sticks the Badger resemble to few japanaese characters Aika from Skies of Arcadia, Cham-Cham from Samurai Shodown and the jungle boy Tommy from Pokémon.

10. Eggman resemble to two Ghibli anime characters, Motro from Castle in the Sky and Kamajī from Spirited Away.

11. Zeti are based off of Oni, a type of demon from japanese folklore.

12. The Sonic the Hedgehog franchise also has an anime adaptation Sonic X and Sonic X is more adpated to some of the japanese Sonic games.

13. Even Sticks the Bager, a non-Japanese Sonic character has appeared in some japanese Sonic medias as well, she appeared both in two japanese Sonic games and an japansese one-shot comic/manga Sonic Comic and has her own Sonic Channel profile.