Metal Fight Beyblade: Baku

Both kids monster anime that also heavily embrace the 'sport' side of their respective competitions. Both have great character & monster designs as well as solid English dubs and OSTs. 

Both second seasons of widely beloved kids anime franchises. Both involve customisable companions whose spirits inhabit parts (bitbeasts/medals) of a apparatus used to battle and compete with other characters (beys/bots). 

Both monster battling anime where young heroes battle alongside partners who are very specific to the worlds these stories take place in (beyblades/spiders). Both in this sense have unique world building and have a lot of the same appeal. 

Both monster battling series. In both the kid characters have one consistent monster partner (bitbeast or spider in each respective series). Both have important teams, cool character designs and unique monster concepts. 

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 second iterations of very similar "battle with toys" kids monster anime. Both have spirits that inhabit the toys. The main cast in each are very alike, thus giving both shows almost the same vibe. Bakugan is clearly and unapologetically heavily inspired by Beyblade. 

Both later generations of monster battling kids anime franchises. Both protagonists Yuma & Gingka have similar personalities. Both feature fictional in-world sports that are played by basically their entire populace.  

Both later generation series of classic kids monster anime & multi media franchises. Both have more future based settings than their original series counterparts in either franchise. Both show off new technologies in their respective worlds. 

Both series are about tournaments with their toys. They are directed by Kunihisa Sugishima and written by Katsumi Hasegawa. 

These are both children's anime from wider classic franchises (Yugioh & Beyblade). Both are later generations and so although not as popular as their respective first generations, both are considered fan favourites amongst the core franchise fans. Both feature a big and important tournament that the main characters all compete in, before of course eventually being pulled into a more pressing larger than life battle against dark forces. 

These are both from classic kids monster battling anime franchises, both are later generations and also second iterations of their respective generations. Both have similar main characters with Yuma & Gingka, and both also have great English dubs and soundtracks. 

Both kids anime with similar themes and premises. Both have a wide variety of monsters/bitbeasts which all have superb designs. Both have solid English dubs and OSTs and it's very likely if you liked one that you will also enjoy the other. 

Both extremely similar toy marketing children's anime series. Both have a large cast of young characters who form teams, battle against the forces of darkness and who have specific partners who battle alongside them. 

Both later continuations of classic kids anime. Both have large casts of lovable characters and wide varieties of their respective monsters with unique designs. 

Both classic kids anime from larger multimedia franchises. Both have great world building, OSTs, characters and art styles. Both feature their unique take on monsters and competitive battles. 

Both kids monster battling anime, both have a large cast of young heroes who must battle together against the forces of evil. While being slightly less popular than other iterations both Tamers and the Metal saga have become almost cult classic fan favourite generations of their respective franchises. 

Both classic kids monster battling anime, in both the monsters battle alongside the heroes and they are powered up by the spirits of their human partners. Both also heavily teamwork focused. 

Both classic kids anime from larger spanning multi media franchises. Both serve as cross promotion for video games, toys and various other products essentially marketed to their audience through the shows. Both have similar aged, heroic main characters that their target demographic is made to identify with and admire. 

Both classic second seasons of similar kids anime & multimedia franchises. Both have unique and recognisable art styles & character designs. Both also have great English dubs and OSTs. 

Both later generations and iterations of classic kids anime franchises. Both feature lots of fun and relatable characters in large fantastical worlds. Both casts of heroes are similar ages as both shows have the same demographic as their target audiences. 

Both children's monster battle anime, both heavily team/teamwork focused, both have monster spirits within a customisable object used for battle (bots,medabots/beys,beyblades). In both the sentient spirits inhabit a part placed within the aforementioned object (the bitbeast/medal), in both they communicate with and battle alongside their partners/owners. 

Both second iterations of classic multimedia kids anime franchises. Both target the same demographic and are series that help their franchises to market new games, toys and products.  

Both monster battling kids anime. Both have great world building, art styles, characters designs and OSTs. Both main characters are similarly energetic and heroic.  

Both second seasons of classic kids anime franchises. Both introduce new characters to an already established cast from the previous iteration. 

Both centre around constellations with them as integral themes, with main characters wielding the power of various constellations. In both the main character has the power of Pegasus, there are also prominent characters with the power of Phoenix, Dragon/Draco & Unicorn/Monoceros, as well as several others.  

Both classic kids "monster battler" series, both have mystical creature spirits within objects (cards/beys). Both have uniquely recognisable art styles & character designs. Both also have solid English dubs and music.