Jikuu Tantei Genshi-kun

Both stories are about kids, cute & powerful creatures and adventures. 

Both stories are about kids, cute & powerful creatures and adventures. 

Both stories are about a clueless, innocent, strong kid who goes on an adventure with his friends in order to collect something. 

Both feature prehistoric influences, time travel & monster companions. Both have similar age protagonists. Both have cute monster designs that can change form to become more ferocious and formidable. Both shows include the main kids parents as important characters. 

Both kids shows that don't take themselves too seriously and have great humour. Both main characters have that radical spiky hair and fight for good & justice. Both anime preach similar morality and have a wide variety of creatures. 

Both kids shows with unique stylistic choices, both have their own technology and creature specific lore to their worlds. Both have great English openings and dubs. 

Both niche kids monster battling anime with similar styles and premises. Both have wide variety of unique monster designs. Both take heavy inspiration from the same type of shows e.g. Pokemon, Beyblade etc. Both are targeting the same demographic and therefore would likely appeal to same people! If you enjoyed one I'm sure it will be the same for the other! 

Both series feature young protagonists who have monster friends with whom they engage in battle. They also both have comically incompetent evil teams. 

Both shows feature a young cast of characters and target the same demographic. They also have monsters that engage in battle alongside the main cast against the forces of evil. Fans of one are more than likely to enjoy the other. 

Both upbeat kids shows that follow a young hero as he is embroiled in a clash against dark forces. Both are pretty light in tone and content and both have plenty of lovable characters with good humour. 

Both follow young brave heroes with epic hair styles. Both kids anime with a wide variety of monsters. Lovable characters and art styles. Both have futuristic motorcycles and themes of futurism in general. 

Both kids anime with the show's heroes befriending monsters / sentient creatures. In both these creatures harbour great power that is best employed when assisted by the human character counterparts. The main characters of the two shows can both be very immature. Both have great art styles as well as character designs. 

Both kids monster battling anime. Both seem Pokemon/Digimon inspired and are targeting that same boom in popularity and audience. Both have a wide range of interesting monster designs. Both have lovable characters, epic opening themes & good comedy. 

Both kids monster battling anime. Both have vehicles that they ride of their own "streams". Both have their own monsters who can be both cute and formidable.  

Both involve people turning into stone and then returning to life after a great deal of time passage. In both the revived characters try their best to make sense of the changed new worlds they find themselves in. 

In both series: - a boy and a girl need to catch/save monsters (in Flint the time detective, Flint will help the main boy and girl character) - need to travel to a different world to do so - get help from a weirdo, but funny professor - the bad guys exist out of a bossy leader who can be angry quickly and two helpers.  

Flint and Goku are very alike, although a lot more similar to OG Dragon Ball, a fan of Flint the Time Detective (Jikuu Tantei Genshi-kun) will likely also enjoy DB in all it's many iterations. They both have a strange over powered main character with a similar look, demeanour & design. They both also have great world building with lots of varied and quirky designs. 

Both lighthearted "Monster Battler" kids anime! Both have similar tones and morality, getting higher stakes and more serious towards the latter half of the series. 

Both feature young heroes who befriend and battle alongside sentient creatures. Both have comically incompetent villains as well more serious ones. Unlike other kids monster battling anime, in both of these the heroes wield weapons and also participate in battles alongside their monster friends. 

Dimensional travel / Time travel. Augmented reality and a time stream riding hover bike. Both kids monster anime that feature futuristic tech!  

Both heavily inspired by Pokemon and the ensuing monster raising/battling kids anime craze. In both casts of young heroes battle alongside sentient creature partners and get entangled in larger than life conflicts against dark powers. Both have flamboyant & similarly styled character designs with the iconic spiky haired look of the era. 

Both monster battling kids anime from a similar time. Both feature a cast of children heroes who make deep friendships and battle against evil powers using sentient creatures. Both have iconic & memorable openings. Both have great monster designs and lovable characters. 

Both kids anime that follow hearty young heroes who ally themselves with sentient spirited monsters. Both eventually see our heroes in a strange foreign world they have to grow accustomed to. Both have rocking iconic openings as well great humour and characters. 

Both shows with prehistoric influenced world building. They both have main characters with black spiky hair, a pure-hearted and simple demeanour with masses of strength and potential. Both main characters also have important family ties that are intrinsic to the plot of the series. 

Both kids monster filled anime, both have smol cute mons and also tough/cool looking mons. Both have evolution/growth of their respective monsters. Both have a human main character who isn't afraid to throw hands with these monsters. 

Both kids anime from the same era who's characters have crazy hairstyles. Both contain wide variety of monster designs that battle alongside the characters. Both have iconic rocking openings. 

Both shows feature a young cast of characters and target the same demographic. They also have monsters that engage in battle with the main cast against the forces of evil. Fans of one are more than likely to enjoy the other. 

In both, little monsters are kidnapped by the villains and turned into evil. They grow into a big, powerful monster then. The main character(s) have to purify the monster and take it back. Also the villain is a woman who think she's beautiful together with some male henchmen. Michel is more serious than Flint, since Flint has more humor in it.  

Both feature spiky black haired larger than life protagonists. Both also have great world building and characters.  

Both kids anime with lots of cute monsters! Both involve some kind of evolution/growth of these monsters with them then able to return to original smaller & cuter forms. Both have great OSTs with charming art styles. 

Both kids shows with ancient beings/themes. Both also have a variety of unique monsters with both cute and formidable appearances. Both also involve evolution/growth of these monsters. 

Both kids anime shows where our heroes continuously defeat a team of comically incompetent enemies. Both have cute little monsters that our heroes collect and battle with that can also evolve and change shape/form to become more formidable. Both have great world building in the way they establish each and every character and monster, and how they relate to the world around them. 

Both kids anime with a young cast of heroes/protagonists who battle against their peers with the aid of monster friends (sentient creatures who've taken a liking to our heroes). Both have great art styles, characters and monster designs. Both shows are good at getting viewers hyped up in similar ways. 

There are often time travels from the future for "save the past". The shows suggest teachings for kids in every episode. 

Both kids monster battling anime from the same era. Both follow young boys on wide spanning adventures making deep bonds and friendships with both monsters and other humans. Both have great monster designs, art styles and OST's. 

Both Pokemon-esque anime intended for a younger audience from the same era. Both follow lovable young heroes who meet, befriend and battle alongside a variety of cute and formidable creatures. 

Both monster battling kids anime that are quite niche and never really lived up to their famous peers such as Pokemon, Yugioh, Beyblade & Digimon. Both feature a dynamic cast of young heroes and compelling monsters.  

Both kids monster anime, both their own unique world building with a selection of varied monster designs, both have these monsters change form and grow in battle. Both also have solid English dubs & OSTs. 

Both niche kids anime with cult followings. Both have varied and unique monster designs. Both take heavy inspiration from more popular/mainstream monster kids anime such as Beyblade/Pokemon/Digimon etc.