This is not a character relations type of post. Because Mello was pulled from another game, this post is meant to let other people know WHOM he met. Because I don't remember EVERYONE except when I see the character, this list is being constantly updated.
Ace Attorney
Franziska von Karma
Miles Edgeworth
Phoenix Wright
AirGear
Akito/Agito/Lind
Ikki
Simca
Spitfire
Avatar: The Last Airbender
Aang
Azula
Haru
Thop
Axis Powers Hetalia
America
Austria
Belarus
Canada
China
Cuba
England
Finland
France
Holland
Hong Kong
Hungary
Iceland
Italy
Germany
Greece
Japan
Korea
Lithuania
Norway
Prussia
Russia
South Italy
Spain
Taiwan
Vietnam
Bleach
Renji
Rukia
Shunsui
Yoruichi
Blood +
Mui
Saya
Chobits
Chii
D.Gray-Man
Allen Walker // Timcanpy
Kanda Yuu
Komui Lee
Lala
Lavi
Lenalee Lee
Miranda
Darkstalkers
BB Hood
Dead like me
George
Deadman Wonderland
Minatsuki Takami
Devil May Cry
Dante Sparda
Eva Sparda
Lady
Nevan
Virgil Sparda
Doctor Who
The Doctor (10th)
The Master
DOGS
Nill
Dorohedoro
Kaiman
No1
Shin
Fairy Tail
Happy
Levi
Full Metal Alchemist
Alphonse Elric
Dante
Edward Elric
Envy
Gluttony
Lust
Riza Hawkeye
Roy Mustang
Sloth
Gintama
Sakata Gintoki
Okita
Glee
Rachel
Puck
Gravitation
Suiichi
Tohma
Yuki
Heart no Kuni no Alice
Alice Liddell
Peter White - The White Rabbit
Hunter x Hunter!
Killua
Gon
Hisoka
Katekyo Hitman REBORN!
Belphegor
Enma
Fran
Gokudera
Hibari
Lambo
Lussuria
Ipin
Mammon
Mukuro
Reborn
Spanner
Squalo
Tsuna
Yamamoto
Xanxus
Kiki's Delivery Service
Kiki
Kingdom Hearts
Axel
Riku
Roxas
Sora
Kyou Kara Maou
Yuuri
Le Portrait de Petit Cossette
Cossette d'Auvergne
Lupin
Lupin
Goemon
Fujiko
The Melancholy of Haruhi Suzumiya
Kyon
Haruhi
Michiko to Hatchin
Michiko
Hana/Hatchin
Nabari no Ou
Yoite
Naruto
Deidara
Tobi
One Piece
Ace
Chopper
Luffy
Nami
Vivi
Robin
Rob Lucci
Zoro
Sanji
Usopp
Ouran Highschool Host Club
Haruhi Fujioka
Kaoru Hitachiin
Hikaru Hitachiin
Honey senpai
Kyouya Ootori
Renge Houshakouji
Tamaki Suoh
Takashi
Percy Jackson and the Olympians
Percy Jackson
The Road to El Dorado
Chel
Miguel
Tulio
Saiyuki
Goku
Sanzo
Sayonara Zetsubou Sensei
Otonashi Meru
Sherlock Holmes [MOVIE]
Sherlock Holmes
Sonic the Hedgehog
Silver
Soul Eater
Black☆Star
Death the Kid
Tenjho Tenge
Aya Natsume
Togainu no chi
Gunji
Kiriwar
Rin
Tsubasa Reservoir Chronicles
Fai D Flowright
Vocaloid
Miku
Wicked
Elphaba Thropp
Wolf's Rain
Darcia
Kiba
Jagara
Toboe
Tsume
X/1999
Kamui
Seishirō
Xena: Warrior princess
Ares
Yami no Matsuei
Tsuzuki Asato