Karnav said:This definitely is mind boggling movie. This is the thing I liked about the movie & the direction.
The style of direction leaves some incidents open for interpretation. This is the interpretation that I come with it [I'll be dividing my interpretation into scenes for better understanding as how I understood this movie]
Scene 1:
The basic romance storyline with the psychological element. The MC is in love with a girl (who in turns is in love with the transfer student which happened to be from future). The MC has a close friend 'The Girl Next Door' (who happens to be in love with the MC).
Scene 2:
The MC & the Girl Next Door were childhood friend. During some crazy rooftop/balcony stunt, the MC died. Some version of the Girl Next Door (probably the future one or from another timeline) tried saving the life of MC (since she is in love with him).
While saving the life, the current Girl Next Door got a leg injury (revealed in the pillow scene) & the other version of her lost her power (revealed in scenes on beach after food).
[I'm claiming other version since psychic powers didn't manifested in this timeline].
Scene 3:
People from future can come to present in two forms-Human form (possible only one time due to strain) & Spirit form (like the MC dog & the ferret of transfer student).
After waking up on beach, while the boys were roaming, the transfer student told the MC that his father once came to this world and MC's grandfather foiled his plans. Then MC revealed he can feel presence of the transfer guy's father here even now. That's how the transfer student came to know the spirit form was his father when he challenged MC to a fight.
The bed scene during that fight was of the time when MC was sitting next to the injured Girl Next Door (correlate with Scene 1).
The timekeeper (probably Earth) tried to get rid of the elements that shouldn't belong here i.e. the transfer student & the spirit ferret. The MC using his power tried saving the transfer student. His grandfather & young sister rescued both from the ill-fate, hence the grandfather fell down at the end.
Scene 4:
The MC decided to take the transfer student to future, since the transfer student lost his power. Additionally, he planned to help the future using his powers.
Since technically MC shouldn't exist in the timeline, his memories are wiped from the minds of everyone as soon as he left for future.
After the year end, the MC returned to the present time with the Transfer student (which is now in Spirit form).
I guess I was helpful in explaining/spoiling the movie for you.