Basically, a template family (good father Marisa treated like a slave, Deibu mother, three Deibu daughter and maltreated Marisa children).
Reimu had the habit of killing the baby Marisa to relieve stress.
One day, Deibu even went to the neighbour's house to take the cute and obedient children (she want children who will obey her unconditionally) and killed the mother. She then killed the whole family after the children said they won't go with her. Those children are not hers, they're scum who tricked her to think they're hers.
Deibu killed the last baby Marisa as usual. She took off the hat and then abuse the child to death.
A man seeing that praise Reimu and with bait of sweets sweets, bring the Deibu family to get their easyness.
First is a Marisa coming home from hunting. After being called a scum, the Marisa decided to teach that baby Deibu a lesson by beating her (like the rule in her house). Amazingly, Marisa never used the stick she had for anything more than intimidation. She also forgive the baby Deibu after she said sorry (Marisa also forgot why she's beating her anyway). Back at home, the baby Deibu is stabbed and killed by the family for losing against a Marisa (slave in their eyes).
The next baby Deibu is sent to a Yuuka and her owner (the picture above). This Deibu is tortured by the sadistic Yuuka by pulling off her braids and then stab her with stick until she turns into like a hedgehog. The family don't feel any grief. At least this baby is not defeated by slave, so they still see her as a Reimu, but also a disgrace.
Father Marisa want to help the child, but she can't do anything until the human allowed her to.
Last, when the Deibu are demanding sweets sweets, the man told Deibu to crush her daughter. What that daughter think is impossible happened. Deibu choose sweets sweets rather than her own child. She also said that she has crushed all the little ones that looks like Marisa.
Hearing that, Marisa gone mad and slammed on Deibu. Marisa doesn't stop even after Reimu is crushed and she's hurting herself by keep on slamming herself to the tree.
The man healed Marisa with orange juice and said Marisa has done well. She can now go and find another wife, make a new family. All this bring hope to Marisa's eyes.
Instead of the despaired Marisa who has lost all hope, he want to crush Marisa who now has great expectation of her future.