Chapter 31 will be connected to a one-shot manga by CLAMP titled Shirahime-Syo, also known in English as Snow Goddess Tales.
You can easily found this manga on mandex

The story itself is quite simple. I'm just giving you a heads-up so that when you read Chapter 31, you'll already know who this character is and what their story is about, which might make the reading experience more engaging and emotionally resonant.

If you'd just like a summary of the story, here it is:

Summary:

Shirahime-Syo is a collection of short, independent stories, tied together by a prologue and an epilogue. What unifies them all is the constant image of falling snow and the presence of the Snow Princess (Shirahime)—a divine figure whose tears are said to become snow.

Each story takes place in a snow-filled setting and revolves around the legend that snow is actually the tears of Shirahime.

🐺 The Mountain of the Wolf's Fang (牙狼の山, Garō no Yama):
Fubuki, a brave young girl, sets out to avenge her father, who was killed by a black-furred wolf with piercing red eyes. But as she climbs the snowy mountain, she is attacked by a pack of wild dogs. Before she can even reach the wolf, she's gravely injured. Surprisingly, it's the very same wolf that saves her and brings her food. Touched by the wolf's kindness, Fubuki forgets her hatred and decides to stay and live peacefully with it. However, fate has other plans.

❄️ The Ice Flower (氷の花, Kōri no Hana):
A young man must part from his lover and promises to return, no matter how many years it takes. The girl vows to wait for him, her love unwavering like the ice on a frozen lake. Thirty years later, he returns, not expecting to find her still waiting. Tragically, she had thrown herself into the lake the very day she made her vow, turning into an eternal ice flower so that she could wait for him forever.

🦢 The Eternal Couple (比翼の鳥, Hiyoku no Tori):
A young man goes to war to prove himself and win the hand of the woman he loves. On his way back home, he gets lost in a snow-covered mountain. Frozen and frustrated, believing he'll die without seeing his beloved again, he shoots an arrow at a pair of cranes flying together—killing the male.

Days pass, and he remains lost in the snow until a strange woman appears holding a human skull and silently points the way. He follows her and, along the way, kills another crane out of hunger—only to discover a skull beneath its wing. Realizing he had killed both members of the loving crane pair, he feels a deep regret. Just as he sees the light of his village ahead, he realizes that the woman who saved him was actually the spirit of the crane he had killed.

**☃️ The Ending:
A young man, lost in the snow, encounters a beautiful woman in a flowing white kimono with long black hair. She is Shirahime, the Snow Princess, who has summoned the spirits of wolves to guide him. But before she vanishes, she reveals that the snow is not her own tears—but rather, the tears of human children who suffer from sorrow and pain.

Thus, snow is the sorrowful tears of human children.