The main character of each of these series has a special heart which has great power. The main character in each series has someone with great powers trying to help them & ward off everyone else.
The only real similarity between Magico and Tubame Syndrome is the basic plot, which is: the protagonist possesses a special heart capable of destroying the world and some people want to have it and use it, while others want to save him\her from harm. But thats where the similarities end. Tubame Syndrome is a so-so harem series, on the other hand Magico is a great action adventure series. If you find the basic plot interesting, you might want to check the other manga too.
Lucy is a seventeen-year-old mage with the power to summon stellar spirits, but what she really wants to do is join a guild - and not just any guild. She has her eyes set on Fairy Tail, a notoriously reckless and outrageous group of magic users who are likely to be drunk or destroying buildings and towns in the process of completing a job! While in town one day Lucy meets a perpetually-seasick boy named Natsu who, through a series of events, reveals to her that he's none other than the fire-eating mage Salamander of Fairy Tail! Lucy is finally able to join Fairy Tail and quickly begins to take on odd jobs with Natsu and his gang for fame and profit. Along with her fiery friend, Happy the flying cat, Natsu's archrival Gray and their overseer the invincible and beautiful Erza, Lucy sets forth for epic adventures that leave an epic amount of destruction in their wake. After all, destroying a city or five doesn't matter as long as they get the job done... right?!
Magic is the key theme connecting both Mangas, but there's also loads of humor packed up with series of adventures. One thing that I also find similar in Magico and FairyTail is the good-hearted storytelling which makes this definitely oriented for kids but also fun for teens and adults. Thumbs up for the gorgeous universes and artwork created by the mangakas.
All Shinta wants is to find a girlfriend, and constantly falls in 'love at first sight' with his classmates. Unfortunately for the boy, none seem to reciprocate his intense feelings, and thus, he does the only thing he can think of – he visits a local shrine to hopefully have his wish granted. Much to his surprise, Shinta encounters a god at the shrine who decides to grant his wish, and the next morning, Shinta wakes up next to the lovely goddess Isana. But all wishes come at a price – it's that time of year when gods throughout the world battle it out for territory, and each deity like Isana must use a human as their champion. Now, Shinta must fight countless enemies for his newfound girlfriend, even though she doesn't seem to want to give him the time of day!
Both Magico and GAN☆KON revolve around a married (or to be married) idiot couple. Both are shounen series composed of comedy and action (and occasionally some drama). It's highly possible that you will like one of them if you liked the other, so give it a go.
Both manga revolve around some uber strong kid protecting the girl he likes. To be honest the rest of the story is crap, but it still somewhat works and since both manga are by the same author, if you found one to be appealing, then you can't go wrong with the other one.