On Ped's (Panisara Pimpru) wedding night on Valentine's day, Ped's close friend Mei li or Li (Sirin Horwang) has drunk too much wine and fallen asleep in Ped's room. Waking in the early hours, she drives back to her home, but has an car accident on the way. As a result, she meets Loong (Theeradej Wongpuapan). He helps Mei Li check her car engine and offers to return her car's wing mirror, but Li demurs and says that he can keep it. When Li arrives home in the morning, her parents and grandmother scold her. Moreover, her father forbids her from driving, so Li has to go to work by public transport.

One night, Li wakes up in the middle of night and go to the roof of her house. She accidentally catches her younger sister and her boyfriend also on the roof. Her sister's boyfriend calls his 'elder' (responsible adult), who turns out to be Loong. After that, Li meets Loong again at a BTS Skytrain station. This time Li accidentally breaks Loong's sunglasses. Li consults with her neighbour, Plern (Ungsumalynn Sirapatsakmetha). Plern helps her by suggesting Li writes her mobile phone number on something and give it to Loong. Li buys a replacement pair of sunglasses and writes her number on box, and arranges to 'bump into' Loong to give him the new sunglasses. After waiting for Loong to call, Li consults with Plern again, and go to a Video Rental shop that Loong visits regularly. Plern uses a trick to get Loong's mobile number, but later goes to work at the same video store instead of giving Loong's number to Li. As revenge, Li uses Plern's mobile to send messages to Plern's 3 boyfriends, inviting them all to the store at the same time. This causes an argument, and when Loong comes in to the shop, he accidentally drops his laptop.

Feeling responsible, Li take Loong's laptop to Ped's husband, but he can't fix it. Li goes to return it at the BTS office. Since Loong is away from his office, she leaves a message with security, but she falls asleep. When Loong finishes work, he finds Li, and they share the BTS to get to their respective homes. As Loong's laptop was so damaged, and the laptop bag was so old, he decides to throw it away. Li picks the bag up out of the bin, and takes it home. There are many things inside including film negatives. Li has the nagtives printed, and finds Loong's pictures with Kob Kavita (Taksaorn Paksukjareon), an actress in "Saint's Tear", a popular television series that plays a supporting role in the film. However the pictures are posted on internet and published in newspapers, as the photo printing shop owner posted them on Hi5 as they were of a famous actress.

Li meets Loong again on a skytrain while he is sleeping. Li tell him the truth that the pictures might have been published because of her, but Loong doesn't mind. Loong tells her that Kob is his ex-girlfriend and they broke up because their time schedules didn't match. When the skytrain arrives at Ekkamai Station, Li suggest to Loong that they watch the stars at the Bangkok Planetarium and see an exhibition about Mcbright comet which will pass close to the earth. Li asks Loong to watch the comet with her in Bangkok when it passes. Later, before the Songkran holidays, Loong asks Li to come celebrate by throwing water. Li, who has already agreed with her family to visit China during the holiday, makes an excuse when she gets to the airport that she forgot her passport, and so can't go with her family to China.

During the Songkran festival, Plern joins them. Li doesn't enjoy the festivities because of her. Li knows Loong's address, which is a guesthouse next to Chao Phraya River. Li changes her clothes and go to see Loong, and finds him asleep. Li falls asleep next to him. After she wakes up, Loong asks her to travel around Bangkok. Loong also asks Li to come to family day at the BTS, as he can take her into the depot. Loong takes pictures, but Li damages the camera.

On the family day visit, Li finds out that Loong is leacing in 2 days time to spend 2 years studying in Germany. Next day, Li goes to Loong's house and finds that his stuff has been packed. Both walk to talk on Taksin Bridge Li say goodbye to Loong at the bridge by saying that she want to be acquaintances only, echoing the breakup between Loong and Kob. Next day, Loong goes to Germany in the morning, but sends Li a box. Inside the box is the wing mirror from when they first met, the damaged sunglasses, Bangkok Planetarium tickets, and the damaged camera, with the memory card still inside. Li opens the memory card and looks at the pictures. Li rushes to Suvarnabhumi Airport to try and stop Loong, but it is too late - his flight left at 8am, and she arrives at 4pm. On that day, the Mcbright comet orbits to the earth. Loong watches the comet on board his plane, while Li watches it as well.

2 years later, Li is working a night shift as a stock broker. While going to work one evening, Li accidentally meets Loong on a BTS Skytrain. Loong has changed to work the day shift and has been back in Thailand for a few months. Both get off the Skytrain at Siam station, which is the interchange station between the Sukhumvit Line and the Silom Line. Li goes downstairs to change to a different line and doesn't turn back to look at Loong. Li gets on her train, but the electricity goes out. Passengers call their friends or family to say the train has stopped. Li's phone rings with an unknown number, and when she answeres it, it is Loong. He asks Li to again celebrate Songkran. Li replies that she is free for the holidays. When electricity comes back on, Loong is on the same Skytrain, standing next to Li. He tells Li that she has his number now, and to record it.

Refer to: WIKIPEDIA

”Anything you’re good at contributes to happiness”

당신이 잘 하는 일이라면 무엇이나 행복에 도움이 된다.

- Bertrand Russell (British Philosopher) -