Boku kara Kimi ga Kienai (which translates to something like "You Can't Disappear from Me" and is in reference to Hotaru always staying on Kousuke's mind) is a standard mid-2000s manga about a girl and boy falling in love and finding a happy ending. It clocks in around five volumes long with 23 chapters (and 1 bonus chapter, I believe), so it's very short.
The basic idea is that Hotaru believes she's in love with her teacher, Kakeru, whom she believed helped her out when she was a middle school student, but the one who actually helped her was his younger brother, Kousuke, who's kindled feelings for her since he first saw her at his archery dojo, and how Hotary and Kousuke become a couple and overcome.
We follow the two through a multitude of conflict surrounding their relationships; there's a best friend who likes the same guy, a jealous ex, conflicting feelings and relationships with the older brother/teacher, parents transferring jobs, insecurities about SO falling in love with someone else, etc... for a manga so short, it creates a new problem in just about every chapter, so seldom are any of them really given much resolution.
The conflict with Hotaru's best friend, Yakako, is probably the best dealt with, since it takes several chapters for Hotaru and Yakako to be friends again. One of the worst dealt with is Kakeru's developing feelings for Hotaru; he's shown to start liking her, but, it just doesn't go anywhere. The manga instead shifts to a sudden "Your dad's moving jobs say good bye to your friends" and then because everyone showed up to beg Hotaru's parents to let their 16 year old stay, they're like "Oh, okay, sounds cool. We had reasonable parental concerns about leaving our teenager here alone but since she has a boyfriend and friends, it's cool."
The art is nice--though I think the girls have eyes too close together--and I think the author makes guys look very pretty. The lines are clean, it's well made. Nothing much to complain about. Very lovely shoujo style.
The story didn't scream of any really problematic stuff besides the guy Mizuna hired to trick Kousuke threatened to rape Mizuna and then like... she dates him and no one calls the cops about him threatening to assault her. It was a pointless plot point, really. Could have been swapped with Mizuna tricking Kousuke some other way. We don't even have anything especially mature content.
It's not terrible for a quick read, but it doesn't have any emotional depth or particular nuance. Just your average fast romance shoujo.
I reread it for this review in about 90 minutes, so it's very palatable.