I don't think you have to feel a certaing way about things. You feel what you feel. Certainly as you said, it may have been good or things would have been different if you had been closer to your sister, but you weren't, and it makes no sense thinking about it now. What you can do is treasure whatever little memories you had with her, i think. In my case, I think I can understand the main character a little. My ex boyfriend commited suicide short after I broke up with him and you can't help but wonder if it had anything to you with you, or if things would have been different if you had done or said something different. Thing is, you can't know, so you have to trust that you did what you had to and, as I said, treasure the memories.
Oh my god !! I'm so sorry !! I was zooming in to read what you said and suddently pressed on the thumbs down button !! Oh god !! I don't know how to reverse it.. I'm so sorry !! Please forgive me !!
I had an older sister who killed herself when I was 8. Because of family circumstances we weren't so close. However, reading this story made me think about how different things would have been if we had connected as the closest sisters. Like Kaede, I learnt the truth behind my sister's disappearance later, by listening to third parties' comments, except that in my sister's case it actually was a suicide. As I said, I was a kid and I didn't get to know her enough so I couldn't feel her loss as this manga's main character. I could feel my mom's pain, as well as people saying how cold I was for not crying for my sister. That's how I grew up thinking I was a cold person. This manga is indeed sad and I regret not enjoying it as most of you. I wish I could cry after reading this, but I just can't...