>>97135455>is there a reason for it other than the fact that they are Marco and Star's exs
Yes, there is, and it's been discussed many times.
Jackie's naturally supportive chill nature compliments Tom's passionate but quick tempered persona. He wishes to improve himself, she’s the perfect one to support him there. She wishes to have someone who genuinely WANTS to get to know her; Tom gets really into his relationships and can provide that.
The Water/Fire thing and the Twin/Twin thing (not to mention "Thomas" in both their names.
The Jackie ”Read my Mind” thing, and Tom’s third eye (because it is said that it is from one’s third eye that one can read minds).
They both have similar music tastes: ”Love Sentence” and apparently ”Heavy Metal” (Jackie has the equivalent of a SvtFoE ”Slipknot” poster in her room, Tom mentions how “Metal” his fire is in ”LLB”.)
They are both portrayed as athletic and competitive in a fun way. ("MCC" and "SS").
Both characters have been shown to put a LOT of effort into their relationships and like to live more in the moment, even when their partners are clearly focusing other places. (”Starcrushed” and ”Monster Bash”)
Both characters have had strangely mirrored episodes since they were both officially introduced in ”Matchmaker”.
Both characters have had issues with "Personal Image" in this series. Tom mentions in "Friend-enemies" how he finds it difficult to change other's Image of him and in "Demoncism" he clearly has a very negative Image of himself. For Jackie, she took interest in Marco in large part because of his confession in "Sleepover", where he promised he'd overcome his "Image of her placed on a Pedestal" and that ”All he knows is she DESERVES someone who WANTS to get to know her" ... which, from everything we've seen of JarCo, Marco didn't accomplish either (he always had something else on his mind).