Mechanically(Focusing in AP) there are some good elements to combine with Midorikatai.
•Fire due to the Burning Rage technique you can buy in Nanhou. It's one of the four techniques that increases the AP gained per wound(Midorikatai has its own technique, so if you want a Build focused on that is: Monkey Yokai with Midorikatai style and Fire element).
•Earth due to its bonuses on the AP gained through Weighted clothes. Combining with Midorikatai. Though it's a pretty low bonuses(Only +1 regardless of your Mastery, differently from the Midorikatai style that's +1 for each level of mastery).
•Darkness/Storm: Both have a technique that increases the AP gained through absorption. Also storm will be important for Mao's version Thunderfall meanwhile Darkness is a good supply for non-Kuro style to what regards events/Increases curse casting ability/is one of the most, if not the most efficient element.
Overall I classify:
1) Fire.
2) Darkness(No, I'm not sucking darkness for being a Kurokonton user. The element is really good. Top-tier reactivity. Helps in many checks. Enhance Curse-casting. Serves as a decent "supply" of Kurokonton and has its own AP absorption technique).
3) Storm.
4) Earth.