Sonic the Hedgehog & the Blade of Courage

Sonic to Yuuki no Tsurugi
ソニックと勇気のつるぎ

Cameo

Dash & Spin: Hyper Speed Sonic
Dash & Spin: Chousoku Sonic· ダッシュ&スピン 超速ソニック
manga

Collection of several short stories, including omake (extra) koma stories, published as an anthology. The stories are often very slapstick. (Source: Wikipedia)

Cameo

Sonic Comic
ソニックコミック
manga

Short comics released on the official Japanese *Sonic the Hedgehog* website, *Sonic Channel*, as part of the franchise's 25th anniversary celebrations. Each comic focuses on individual Sonic characters featured in the Character Profiles on *Sonic Channel* often featuring slice-of-life moments or references to their backstory in past games. (Source: Sonic Wikia, edited)

Cameo

Shadow the Hedgehog
Shikkoku no Harinezumi Shadow the Hedgehog· 漆黒のハリネズミ シャドウ・ザ・ヘッジホッグ
manga

Manga series focused on Shadow The Hedgehog in order to promote *Sonic X Shadow Generations*. Shadow and Maria live on the Space Colony ARK, but one day they are suddenly attacked by the Earth Defense Forces who are “disposing of dangerous biological experiments”. Shadow and Maria try to protect each other, but Maria is hit by a merciless bullet…? (Source: Shogakukan)

Cameo

Sonic the Hedgehog 3
Sonic × Shadow: TOKYO MISSION -Episode 0-· ソニック × シャドウ TOKYO MISSION -Episode 0-
manga

A manga booklet given out to Japanese movie attendees for *Sonic the Hedgehog 3*.