Yurizon

This is a story set in the near future. One day, a cheerful but slightly shy high school girl, Amami Ueshita, receives an email from a mysterious sender saying, "I love you." Although shaken by her first love confession, Amami heads to the meeting place written in the email, intending to meet the man and reject him properly. Little does she know that this is the beginning of a major incident that will shake the world. Girl meets...? A love story like no one has ever read before begins now!

(Source: Home-sha, translated)