Ru: Taiwan Express (2020)

In 1999, a general trading company in Tokyo celebrates because Shinkansen of Japan wins priority negotiating rights for the Taiwan High-Speed Rail. Tada Haruka has been working at the general trading company for 4 years and she is sent to Taiwan for work. When Tada Haruka was a university student, she visited Taiwan for the first time during the summer. During that time, she happened to meet a young Taiwanese man Eric and he showed her Taiwan for a day. She lost contact with him after that and she could not find him again. She then sealed away her thoughts about him in her mind. 6 years later, Tada Haruka arrives in Taiwan again.
(Source: AsianWiki)