[sirn]

Since this arc has already ended, I guess it's okay to spoil (or rather, summarize):

Spoiler for Events summary and term explanations:

1. Hitagi suffered a well-known disease with an extremely low survival rate.
2. Her mom want her to be saved, so she joins a frantic religion.
3. Hitagi received a surgery and survived. Her mom believes she's survived because the frantic religion.
4. Hitagi never talks with her mom again.
5. Third year of junior high school, her mom violate the religion's doctrine, she offered her daughter to the leaders.
6. Hitagi managed to escape the rape attempt by the leaders but that cause her family to break down.
7. Hitagi meets the Crab, cutting the bond with her mom with her weight as compensation.

The reason Hitagi does not get dressed is probably because she want to show Koyomi her surgery traces along her back.

Term explanations:
Kani (蟹 Crab) → Kami (神 God)
Omoi (重い Weight) → Omoi (思い Feeling)
Omoshikani (重し蟹 Weight Crab) → Omoishigami (思いし神 Feeling God) → Omoi, Shigarami (思い、しがらみ Feeling and bonds)

From the Otona Anime interview, looks like they unable to get the rights to use some trademark or copyrighted name for the anime series, so many name-calling parody have to be removed. Oishi also said Mayoi Snail atmosphere will be very different from the first chapter, so I'll keep my fingers crossed. Please remove the WTF Directions and do it properly, Shaft.