Changbin and Yongbok go to buy bicycles but fail due to the high prices. They then decide to rent bikes through a bike-sharing system and film themselves riding at Olympic Park with the help of Changbin's sister. Changbin and Yongbok have fun riding and posing for the camera, and Changbin expresses his desire to perform a concert at the Olympic Gymnastics Arena in front of their fans, STAY. They eventually return to their dorm, but Changbin decides to go for another ride alone and films himself enjoying the scenery and music.
Here are the key facts extracted from the text:
1. The speaker and someone named Changbin went to buy a bicycle.
2. They couldn't buy a bicycle because they didn't research beforehand and there were too many options.
3. The speaker received advice from a friend to research before buying a bicycle.
4. The speaker and Changbin took a walk near Olympic Park.
5. The speaker's older sister is at Olympic Park.
6. The speaker met Changbin's sister and she filmed them riding bicycles.
7. They bought couple helmets but didn't buy a bicycle.
8. They used a bike-sharing system to rent a bicycle.
9. The speaker rode a bicycle for the first time in 12 years.
10. The speaker's sister helped them with their hair before filming.
11. The speaker and Changbin rode bicycles at night and enjoyed the cool wind.
12. They visited the Olympic Gymnastics Arena.
13. The arena can accommodate 12,000 to 15,000 people.
14. The speaker wants to perform a concert at the arena for their fans, STAY.
15. The speaker rode a bicycle again by themselves and enjoyed the wind and music.
16. The speaker created a playlist of songs they recommended to STAY and listened to it while riding.
17. The speaker hopes STAY can enjoy riding a bicycle to relieve stress.