Shinobi Life
Complete | konami shouko | 2006 released
I read this a while ago so let's see if my memory serves at all. I remember liking the story (probably wouldn't reread just because it's got a lot of typical shoujo tropes and once you've read it once you'll be bored trying again). It did have some interesting plot twists, though, and I thought the author did a great job tying together all of the time travel events between the past and future. The beginning was pretty damn funny as well, when he tried getting used to the future for the first time. I was really sad that everyone except Renkaku got saved in the end, though. I'm a sucker for characters like him who are nice with a hidden pain.
Shinobi Denai To!