It is a fairly good story, but if you really want to enjoy it you have to read the whole thing in one go. (probably will take you a few hours)
It gets a bit confusing if you stop in the middle for a few day and then continue from where you left off.
The story has like 3 main parts, each has it's ups and downs:
1) How they meet
2) The new guy
3) Time traveling and then resetting everything back to the moment before they meet on page 9 chapter 1.

Part 1 - It starts off fairly lighthearted and fun. She basically has these erotic dreams about a guy she does not know - he end up being this popular novelist how is also a university literature professor. You also find out that she had an accident 6 months ago saving a dog and is given blood transplants by a spiritual lady called haruko. as a result of the blood transplant she starts having memories (among other things) of the now deceased haruko. Haruko however had a 4 year old son who also has spiritual powers. Upon seeing her the boy instantly senses his mother's presence in her and from that point onwards can't live without her. So she reluctantly agrees to stay with them for the boy's sake. This is like a romance story so you can kind of imagine whats going to happen next - she falls in love with him. They have a few troubles in the beginning but they sort it out.

Part 2 - Her mother decides to visit, so she quickly goes to a friend's house and lies to her mother telling her that she lives with her friend. The mother comes to the friend's house with a surprise - the new guy. The new guy is someone who she once had a crush on and was the doctor who took care of her when she was hospitalized (but at that time he was seeing someone else so she said nothing). the doctor has now become a musician and when he meets her at the friend's house he ask her to marry him. she freaks out; her mother pressures her so she goes back to the kid and the novelist. the mother and musician secretly follow her and they find out the truth about where she lives. The mother gets angry and threatens to take her back home unless the musician is allowed to stay with them (to keep an eye on them). Complicated crap happens she get angry at the novelist and sleeps with the musician who later asks her to go with him to australia - she agrees (hope i didn't loose you yet). On the way to somewhere she sees the novelist and the boy walking, she gets out of the car and he tells her that he is visiting the place where haruko and his brother died in the accident. he convinces her not to go and the musician subsequently gives up on her and goes to Australia.

Part 3 - (This is the complicated part that some people got lost at so pay attention :) The boy and the novelist have a funny argument and somehow the boy uses his spiritual powers to send her into the future. she meets the boy in the future when he 17 years old, but he does not remember/know who she is, (this is the only anomaly/loophole in the whole story) so she lies saying that she a distant relative and then they have a little adventure where she teaches/reminds him that he has these powers. he then tries to send her back to her time (the present) but not before she sees that haruko is actually still alive!!
However instead of being sent to the present she is sent to the past before haruko's accident but just after her own accident (just after haruko donates some blood to her). There she meets haruko, her husband(who the novelist's twin brother) and the boy who is now an infant. she also meets the novelist there but obviously nobody recognizes her. They all have a chat and haruko mentions that she and her family were going on a hot-spring trip. a while later when she is playing around with the infant he somehow teleports her back to the present. after a while she finds out that haruko and her husband had died on the way to a hot spring trip. Feeling guilty that she could not save them, she asks the boy to send her back to that time just before haruko's accident. However when the boy was teleporting her to the future he saw the image of a dog on the tv. so instead of teleporting her into the past he only sends her soul into the past. however her soul is now trapped in a dog. she now sees that the dog that she had earlier saved was actually her (and she becomes completely shocked). she also sees how haruko saved her until the ambulance comes. Haruko then takes the dog home but obviously nobody can communicate with her, haruko then arranges for the dog's owner to come and pick her up, however she struggles and runs away. the novelist of the past then sees the dog and picks her up and not knowing what to do she calls out for the novelist in desperation. somehow this yell for help travels through time and is heard by the boy and the novelist of the present. the novelist then asks the boy to send him to the past, which he does. but once again instead of sending the whole body only the soul is sent. This time the soul ends up in the body of the novelist from the past. together they save haruko and her husband from the accident. Haruko then warns them that because they have changed the original course of events they will most probably not remember anything when their souls go back to normal (because they would not have met each other if haruko had not died). after being explained that, maiko and the novelist vow not to forget each other and then haruko sends their souls back. The story then goes back to just before the two meet each other. Upon seeing each other they instantly regain their memories of what had happened and they run and hug each other, i.e. they live happily ever after. The end.
Damn this took a long time to type up (1 hour) i hope it was useful.
So basically a great story, perhaps a bit complicated but it all clicks together in the end (exept that 1 anomaly which 1 could not work out, if you do, please tell). It is a sweet short story which is definitely worth a read.

slept with that other guy it killed the manga in an instant for me.

It really should have done without incoming guy cliche. I still finished it reading but was disgusted and not interested in it anymore.