Ichirou is a mysterious young man who appears one day at a hotel in Okinawa. 

Maise is stuck spending the summer after her first-year of high school helping out at her family’s hotel in the sleepy seaside town, but things become a little less sleepy once Ichirou, a mysterious young man, checks into the hotel. It seems as if only Maise and Ichirou can see the strange, sudden apparitions: the hotel lobby and the room transforming into an aquarium, a giant tree erupting from the floor or the rowdy monsters laying claim to the hotel restaurant. Maise vows to figure out not just what’s causing these odd occurrences but why Ichirou has come to this remote town in the first place. 

(Source: GKIDS)

The wondrous story is set in motion one summer when Maise Higa, a listless first-year high school girl who works part-time at the front desk of her family's hotel in Okinawa, meets an "Ichirou Suzuki," a mysterious youth who came alone from Tokyo as a hotel guest. Since Suzuki's arrival, "deji" things have been happening around Maise, like fish swimming around the room or a giant banyan tree smashing through the hotel ceiling. 
 
(Source: Anime News Network, edited)

Music video for the song Otogibanashi no Youna Kiseki by Aoi Kubo. 
The music video features the anime's two main characters, Maise Higa and Ichirou Suzuki, and depicts their emotions and past stories before they met, such as why Maise decided to spend her summer vacation working part-time at a hotel and why Suzuki came to Okinawa. 

(Source: Crunchyroll) 
Note: The song featured in this music video was also used as the ending theme for the anime Deji Meets Girl.