Guess again~
Hint 01: It started publishing in 1999.
Hint 02: It has less then 50 chapters.
Hint 03: It's name starts with an A.
Hint 04: It's not a shounen manga.
Hint 05: It ended naturally.
Hint 06: It's name has two words in Japanese with an "-" as interception.
Hint 07: It's lead character is called
Ikuru.
Hint 08: It has more then 40 chapters.
Hint 09: It's full of mature topics filled with tragedy.
Hint 10: It's about a dying person and his struggles through his remaining moments.
Hints added~