I'v been reading Change 123 and so far I've loved it. I was hoping someone could give some advise on series that are like it.

I also enjoyed Historys Strongest Disciple Kenichi and Angel Densetsu so anything like that would also be appreciated.

Othello (shoujo)
Gacha Gacha

and maybe these can help?

http://www.mangaupdates.com/showtopic.php?tid=7047&hl=split%20personalities
http://www.mangaupdates.com/showtopic.php?tid=6627&hl=split%20personalities
http://www.mangaupdates.com/showtopic.php?tid=9717&hl=split%20personalities

[url=http:////www.mangaupdates.com/showtopic.php?tid=42718][img]http://i366.photobucket.com/albums/oo105/CatzCradle64/Avis-Sigs/FunghiPower_zps2a00ba56copy_zpsfc03990e.png[/img][/url]

So do you want manga with split personalities or typical shounen manga... change 123 and kenichi are really quite different

[img]http://i136.photobucket.com/albums/q162/anghmw/Conundrum.gif[/img]
What a tangled web we weave, when we practice to deceive
:=EXITUS ACTA PROBAT=:

If you're just looking for ecchi and action then try Freezing and Sekirei

Not looking for split personality just shounen manga