Sekokechi Gimai ga Subete wo Ushinatta Hanashi

There's something bothering our main character, Reimi. And that's her extremely cheap and stingy sister-in-law, Kae-chan! Kae took home all the decorations from Reimi's wedding. During her baby shower, it seemed pretty obvious that Kae had just added her name to the present Reimi got from her husband's parents. And the gifts Kae actually did send for the baby were used and dirty... How stingy and cheap can a person be?! "It doesn't really matter..." "It's not worth bringing up..." At least that's what Reimi grit her teeth and told herself, but one day, Kae went one step too far... Source: K Manga Official JP: Mecha Comic (as mentioned by the author and credited by Kodansha), Shounen Sirius (directed from ARTEMIS by sirius) Original webnovel: Author's blog