Mahou Shounen Heart Magic

Mahou Shounen Heart Magic 
魔法少年ハァトマジック 
[Magical Boys Heart Magic]

About: The magical kingdom of トータティス (Totatis?) were under a crisis of sudden darkness and the lack of warmth and light. The King sent his three princes to Earth to collect the power of kiss of love to create Philia crystals to break the curse and save the kingdom. The rules are that it has to be from one girl, and the feelings must be true.

Kitten Dagda (CV: Suzuki Yuuto)

The first prince sent was Kitten and he has the magic to transform into a cat. All of his magic were summoned with cat breeds' names. The MC found him in his cat form that resembled her previous cat she just recently lost. Kitten at first used his hypnosis magic to get to kiss her but only afterwards when he checked with his talking assistant like creature/object he called Compact that none of the kiss produced any power to his Philia creation. The Compact had to explain to him again that the kiss needs to be of mutual affection. Kitten told MC that he was not the Queen's son but he was once a cat(?) that she took in out of kindness and raised as her own child. He was cared for and cherished in the castle until the Queen suddenly died. He took the duty to create Philia and save the kingdom was to get approval from the King to stay in the castle and not cast away. However in the end after making up and properly getting involved with the MC and eventually managed to create the Philia, he asked the King to stay on Earth instead and lived with the MC.

Chouchou Midir (CV: Yonaga Tsubasa)

The youngest prince, his magic is derived from the shining stars. He is quite flaky and not exactly following the rules. He initially did not seriously wanted to collect the power to create the Philia crystals. He fell off his flying broom and was saved by the MC who was stargazing that night. Decided she would be a good contributor for his duty, he asked for her help and she agreed after a few convincing words. But he secretly summoned his doppelgänger to get to the whole kissing process. MC noticed that the person kissing her is not the same as the person asking for her help so the next time he came to apologize, she didn't give hers before hearing his explanation. Chouchou told her that being a prince means that he needs to be good in everything that he does, especially with magic. His doppelgänger was born one day through magic when he wished really hard that he would have someone else to do the things that he would not rather do himself, and he had been relying on the copy for a long time. MC told him that it's not good to continue to run and hide to the things he didn't want to face and Chouchou finally got his feelings honestly conveyed and fell in love with MC. There is some scene where his copy wanted to assume his position since Chouchou dismissed him quite easily once he no longer have a need for him. In the end Chouchou asked his doppelgänger to stay and live in his stead at the kingdom while he himself would stay on Earth with MC.

Joel Dagda (CV: Takahashi Naozumi)

The crown prince, Joel, is a bit serious in personality, though not in his mission to make the crystal. When he first met MC, after asking her help to make Philia, he kept checking his Compact whether or not the percentage rises or not. Joel carried the burden of using time magic and would sometime be sucked into the 'space between time'. Within that realm, time would stop and he would not feel any bodily needs like hunger or sleep, but he is aware. What he could do was sit down in complete silence and solitude, waiting for time to start again. It would last a very long time most of the time and that made him felt lonely all the time, even when he started dating the MC. Though this time around, his prison in between time was cut short when the MC accidentally got trapped with him and he kissed her out of his affection for her. The kiss summoned the Philia magic and freed them from the prison. He went back to the MC on Earth after delivering the Philia to the King and they lived together ever since.

Final say: If you like youthful, toshishita type of characters with a lot of kissing scenes, this one is for you. The stories are short and nice, but I must have missed some details to them due to my current level of Japanese proficiency. For example, I have no idea why only Kitten and Joel shared the last name but not Chouchou, since only Kitten that was adopted. Maybe there's some explanation in Chouchou's volume but I can't seem to pick out the details. Drop me a comment if you know why that is.