Monster Rancher/Heartwarming

The game series

 * When a Monster's 'Likes' trait changes to your name, meaning they like you more than whatever was there previously.
 * When a Monster likes you so much they want to play with you.

The anime series
"Genki: Mocchi, listen. If I or the others don't make it back, someone has to find the Phoenix...
 * In episode 1, Genki has just met Mocchi when the latter is threatened by the Black Dino Squad. What's Genki do when their leader threatens to make the young monster a slave? Kick the Black Dino in the face. Big Brother Instinct status established.
 * In the second episode, Genki and Holly unlocked a Spot Dino, and gave it to an elderly couple they'd befriended earlier who wished for a Monster to love.
 * In return, the couple gave Genki shoes to use alongside his rollerblades, and a cloak. These were worn throughout the series, and it all started here.
 * Also in the second episode, Mocchi ran away because he thought Genki didn't love him. Genki went out to look for him and soon got lost. When bad guys cornered Genki and asked him where Mocchi was, Genki wouldn't tell. Mocchi then realized how much Genki loved him and ran out to save him.
 * Genki and Holly bonding with Tiger after his pack was killed.
 * After hearing Holly's tear-jerking story about her past, Genki and the others sing a silly song to try and make her laugh.
 * Although the really heartwarming bit from that sequence is Golem gently picking Holly up, whereupon she stands up on his palm, throws her head back, eyes closed and a big happy smile on her face, and pronounces simply, "From now on, the rain will make me happy."
 * One from "Pixie's Defeat" where Genki and Mocchi have to split up to help save the others. Mocchi is reluctant to leave, but Genki insists.

Mocchi: ...I understand, chi. *hugs him*"


 * In "Suezo's Secret Weapon," Suezo is depressed because he can't catch up to the others' abilities. Genki and Mocchi try and train him in telepathy, but it fails, so Holly gives him a pep talk to cheer him up. This pays off when he learns how to teleport, saving them from going down a waterfall, and everyone is genuinely impressed.
 * Golem befriending Undine, referring to them as soulmates.
 * Tiger and Grey Wolf's time as puppies.
 * The entirety of "Holly's Happy Birthday", where Holly gets a surprise birthday party from Genki, Mocchi, Golem, Suezo, Tiger and Hare.
 * The second season finale was this combined with a Tear Jerker.