Taichi is complicated. Arata's relationship with his father (and how that plays into his father's relationship with his grandfather) also seems to be something to look out for. A good episode overall. It's all still clearly just setup for the real story set when they are teenagers, though, so I maintain that that is what I'm looking forward to.
With regards to Chihaya's sister, she actually recaptured my interest a bit after disappointing me last episode. I like that she values the admiration of her little sister--that's cute. It also gives me hope that their relationship will play an interesting part in the future story (it helps that both Chihaya and her sis are/should be quite gorgeous,
. Gotta make use of that animation and artstyle.).
On the karuta, I quite liked what they showcased of the team play, that was interesting. In the future, Chihaya should also (I am sure) be better with memorizing the poems on an individual level, so I'm sure we will see more depth there as well. That's what I'm most looking forward to for now. Arata's overwhelming skill and now pedigree have honestly played out more like plot elements than actual points of accessibility or interest into the game for me thus far.