Hikaru to Hikari

After being coaxed into crossdressing by his older sister, Hikaru Futaba ends up participating in a girls-only singing contest under a female disguise. Soon after his performance, Yuuto, Hikaru's friend, falls in love with his female alias. In addition, the class representative Sumitani-san also falls for him after discovering he crossdresses. How will this love-triangle play out?