Stack markers for days by looping the 2k1 combo Yui and backups. Pray for a bunch of clean markers and laugh as people are forced to anti change a 1/0. The topcheck Haruna level 1 combo is there mostly as a backup. There is a minimal amount of red to let you play the Nana level 3 so be aware of when you'll need to level red up. This was my original animals deck before set 2.
Depending on how useful you find the red you can drop it entirely and just focus on the early play heal. Level 3 Yui is to use against decks with anti damage events but you could also add a couple more since it just replaces itself on play.
I personally never messed with the 2/1 Risa that freefreshes the deck because your only way to get specific cards is brainstorming and lvl 3 Yui, but if you dropped red you could probably toss that and the level 0 it requires in.
Something else to keep in mind is that the TD actually has several animal trait cards in it. You can run the level 1 Nana combo if you'd like (IIRC 1/0 5k, pay 1 salvage on attack with a stock soul) OR if you're feeling extra spicy there are a bunch of vanilla YELLOW cards with Yui in the name (and thus animal trait) so you can splash in Darkness Plan and have an anti damage.
Have fun, and remember to feed the beast.