The main character of each of these series has a special heart that everyone wants to take possesion of, to gain it's immense power for themselves. The main character in each series has someone with great powers trying to help them & ward off everyone else.
If you like idiot couples then Ore ga Akuma de, Aitsu ga Yome de. and Magico should should suit your taste just fine. Not to mention, both of those feature makeshift families of sorts (though those are slightly different between those two series).
Haru Glory lives peacefully on Garage Island with his sister. One day, Haru fishes a strange dog-like creature named Plue out of the ocean, and soon after meets its master, an old man named Shiba. With this man comes terrible news: the world is in peril, for the evil organization Demon Card is attempting to conquer it with power-giving stones known as Dark Bring. To combat this threat Shiba has spent much of his life fighting back with Rave, a Holy Bring; and the Ten Commandments, a sword it powers. When members of Demon Card arrive at the island, Shiba discovers that Rave and the Ten Commandments will now only respond to Haru, making the young boy the new Rave Master. Armed with newfound power, Haru and Plue set forth to put a stop to Demon Card.
Rave master and Magico resemble each other with innocent and sweet love-relationships common for non-ecchi-shounen.
Both have some action and interesting storyline and they include such subjects as family, trust and friendship.
If you liked one, you will like the other too since their style is very similar.
Looking for cute married couple in a shounen manga? Samurai Usagi and Magico are the way to go.
In a bizarre fantasy world, students known as meisters are trained at the illustrious Shinigami Weapon Meister University; but the tools they wield are no ordinary weapons! Each meister is paired with a human-like being who can transform into a weapon at will; and after defeating a pre-kishin - a human whose soul has darkened - the weapon eats the soul within it. A meister's ultimate goal is to collect ninety-nine pre-kishin souls and one of a witch so that his or her partner will become an all-powerful Death Scythe. Maka and her partner Soul Eater; Assassin Black Star and his partner Demon Blade Tsubaki; and Shinigami's son Death the Kid and his partners the Demon Twin Pistol Thompson Sisters each vie for their ultimate goal, but plenty of challenges and adventures lie in their way!
Magico and Soul Eater are rather different, but if you liked the art style in one of those, then you ought to check the other one too. I believe that in this case, the art style is enough a reason to write a recommendation.