My Stepmother and Stepsisters Aren't Wicked

Nakamura Miharu, the illegitimate child of a certain noble family, lived a poor but happy life with her mother.
Then, one day, her beloved mother passed away, and Miharu was taken in by the main branch of the Kozo family. Feeling ashamed of being the child of a concubine, she bowed deeply in apology, prepared to accept any treatment.
However, her stepsisters welcomed her with great hospitality, giving her a bath and dressing her in pretty clothes. Furthermore, they began a major cleaning to convert her father's study into her room.

There's still so much that Miyu doesn't understand about the Kouzou family.
One day, Marika asks her to meet the Kouzou family's bodyguards, and Miyu imagines burly, intimidating Japanese soldiers, making her nervous.
But what awaits her is Gungnir, a round, fluffy little dog.
She's instantly captivated by Gungnir. However, Gungnir has a tragic past, and that incident caused him to lose his voice.
As Miyu learns about Gungnir's origins, she begins to relate them to her own past—

Miyu is being tutored by Marika. She studies desperately to live up to the name of Kozou, but things don't go as planned and she becomes discouraged.
Marika tells Miyu about her past.
Hearing about Marika's past puts Miyu at ease. Just then, Arisa comes in to let Miyu take a break, and the study session is temporarily interrupted.
Miyu and the others head to the terrace for tea, but there is a loud crash from the garden! It sounds rather ominous──