Or, as a recent review on the story asks, are both Ragyo and Satsuki mentally ill and unaware that they are?
Likewise, we get Rei's suicide and her motives, did she commit suicide out of fear or did she have other reasons?
In Raindrops we have this with a Secretly Dying Ryuuko and her illness. Did she really grasp the severity of her illness and just didn't want to upset her sister but went to live with her anyhow or did she know she was dying and, due to denial and her stubborn nature, refused believe it until the end?
Creepy Cute: According to a few commentators, her poem I'm Hungry is this.
Fridge Brilliance: Doki having cerebral palsy makes a tad more sense if one remembers that cerebral palsy tends to be more common in multiple births. Likewise, it's not uncommon for those who have cerebral palsy to have eye problems, nearsightedness being one of them.
The chapter titling of Through Thick and Thin is a reference to cancer stages.
Nezumi having bad eyes is because she's a rat youkai and, if one can remember, a lot of tunneling and nocturnal rodents, rats (and mice) especially, tend to have poor vision.
Harsher in Hindsight: She did allude to this trope with a painting she titled "Cruel Irony", said painting being a still-life of a vase with lycoris flowers and with Ill Girl Rei in Feel, who suffered from repository problems and is implied to has later on passed away. The basis for those things was that her maternal grandmother was in hospice and had passed away.
The Reality Subtext behind the story Broken Gate makes the Downer Ending a lot worse, especially since she wrote it based off of an abusive situation she endured.
Jerkass Woobie: Toki. She started out as this in Time Heals No Wounds II, before her redemption and change of heart. To further drive the point home, she wasn't always like that and was rather sweet, however, deep within the pain from being abused and then neglected (on top of that almost dying of cancer, after it was allowed to reach later stages) eventually poisoned her, allowing her personality to be tainted and turning her into the mentally ill intimidating wreck that she is, making sure no one could ever hurt her again and that she would be one to hurt, in control, and to be betray, just like it had happened to her. The quote below is just a summary:
Brownie: Toki was once a sweet shy innocent girl who only wanted to be loved, according to Jinx and Spin, but the birth of Frailine turned her shallow, cold, cruel, dominating, calculating, and worst of all, sadistic.
Nightmare Fuel: A few of her writings but the poem "Broken Leg" is scary on a Reality Subtext level, as she wrote it based on an obsessive intrusive thought (or vision) she had where she had broken one of her legs, was alone, and couldn't get help.
A bit more overt with the poem $900, and it's more explained with the description, "Health insurance or, rather, money can be a nice thing. Some people have one, some people have the other, and some have neither." Like the abovementioned, nothing more will be said on it.
Stoic Woobie: An emotionless Nezumi in Broken Gate. It's clear her life has never really been happy and she only wanted to be free but that all changed when she and her older brother Ryuuji had a fight, over the latter's mistreatment. Besides roughly 100 years pragmatics and guarding the gate, it's no surprise she's emotionless, as, odds are, her having emotions would probably make her situation worse.