Yui is an engineer major with no girlfriend, he also hasn't fallen for anyone because he gained a texting pal named MIKI, through a misdirected text message, whom he now sends text to regularly. During this time, there's the super popular Juji attending the same school as Yui. When Juji is sending a text to someone he changes his expression to a happy one and Yui see him. It produces an empathetic feeling within his heart...

(Source: Ten Manga)