To Love Ru/Heartwarming

For a harem comedy, there is a great deal of heartwarming moments interspaced throughout the manga and anime.

"Yami: What I'm thinking right now... is only one thing... "I am glad that you're alive." Just that... Tear..."
 * Rito and Mikan's relationship is all kinds of heartwarming, though you may have to overlook the Incest Subtext.
 * When Mikan gets sick, Rito takes over her chores and tries to cook her soup. Due to Lala's interference he messes up the cleaning and due to inexperience messes up the soup. Mikan chokes down the bad but not inedible soup and thanks him for the effort, calling him Onii-chan, which she very rarely calls him.
 * When Mikan feels lonely because Rito has been spending so much time with Lala, Rito immediately takes her out to try and cheer her up. Eventually he succeeds.
 * When trying to stop Momo from sneaking into Rito's bed, Mikan tries to ambush her by hiding in Rito's bed while he's sleeping. Then thunder and lightning start, and Mikan gets scared. Rito, still asleep, immediately rolls over and hugs her, trying to comfort her. This is apparently something he's been doing since they were children whenever she got scared.
 * Rito calls Mikan a "special existence" to him, even more than a sibling, while describing their relationship to Yami.
 * One of the things that may've warmed Yami up to Rito came when she and Mikan body-swapped (deliberately; Mikan wanted to play with the "Transform" ability for a while, and Yami didn't mind). In Mikan's body, she decided to do Mikan's chores, but her unfamiliarity with things like a scrub-brush caused Rito to think she might be sick. (Somehow he didn't notice that was Yami's speech pattern coming out of his sister's mouth.) He had her sit down comfortably while he took over her chores again, and later brought her tea. She commented on the spiritual warmth of his making tea for his sister, and later told Mikan she envied her a bit.
 * Lala and Haruna trying to comfort Rito after he is forced to confess his current feelings about Lala in the Trouble Quest arc and things become akward. In the end, Haruna talks to him and allows him to admit that Lala is an important person to him without embarrassment, and Lala expresses her thanks that he's returned to normal and her regret that her younger sisters forced him to do something that he clearly didn't want to do.
 * Lala setting things up so that both Mikan's and Rito's parents can come home for Christmas. To put this into perspective, this is the first time they've all been together for potentially years.
 * Finding out that Lala intentionally let her inventions run loose in order to stop her younger sisters from fighting each other. She really can act like an older sister.
 * Yami refusing to battle Mikan when the latter was under mind control. She cared about Mikan too much.
 * Chapter 14 of Darkness: Yami tells Rito about her past, and even embraces him in her sleep. Also, her thought of "I want you to hold me."
 * Also, Yami's relationship with Tearju Lunatique, her creator.
 * Darkness, chapter 15 : Yami meets again with Tearju Lunatique.