Looking for a manga

I'm looking for a manga where the main character is a female writer, her boyfriend lives with her. One day her boyfriend goes to a family funeral and ends up bringing his cousins kids to come live with them because both parents passed away. The first scene of them seeing each other was when they first came to her house and she accidently threw salt at them to not bring bad omen. In the story the older kid (probably in jr or high school) at first was shy to open up, but after an incident where his stomach was hurting (due to constipation) changed a bit and open up. Trying to remember more of the story or reread it. Looking to see if any of this rings a bell. Thank you (=・ω・=)