Forgotten Title Sickly MC obtaining a heathly body after death, is rom-com and discontinied

So I forgot the title and names of the characters of a Japeness novel I have read long before.
It start with MC dying while feeling apoligitic about her parents needing to pay her medical pills for nothing.
She's quite naive and simple and quickly accept the angel's suspicious offer of putting her unto a girl of the same age who died the same moment as her, without thinking much.
The angel even whisper that the girl's (Aya or something along the lines) life is complicated.
When MC woke up she find that the OW died by sucide and she didn't understand why such a heathly young girl would kill herself. (16 years old)
She find her relationship with her family (mother and brother) very bad.
The father is always away and never mentioned enough that MC thought he's dead.

Ah! I remembered now the name of OW it was Aika! and MC call her Aika-chan on the inside.
So now MC is still fixing all the crap of Aika.
It was quite interesting and I didn't find MC being dense annoying.
She also mention that Aika-chan was very beautiful and that she cannot get why she wear heavy makeup enough to be a clown.
So MC who's an only child became a brocon to her new younger brother who was seriously being bullied by Aika during childhood. He became a tsundere siscon quite fast but it didn't seem forced.
Describtion made one laugh as it's quite funny.
MC fall for Aika's ex and doesn't know how to convey it when she knew that Aika forced him into dating her so she'll not bully his 'lover'.(she isn't, it was his own one-side feelings to a childhood friend)
Something is fishy about the bullying and there is hints everywhere that it wasn't original owner's doing and the bullied girl knew and wanted to speak up for Aika but was shut down by Aika herself.
So MC is seen as Amnestic girl.
MC's new father doesn't make appearance until around 30 chapter.
S. O. S! Pleeeeeeeaaase!

 

Soshite Shoujo wa Akujo no Karada o Te ni Ireru.
Was interesting, but sadly TLs hv been dead for a long, long time.

 

LOVE YOU! Ah! Thank you very much!