The second season of Kanojo mo Kanojo. 
 
After their hot springs trip, Naoya continues his relationships with both Saki and Nagisa. Bringing along Milika (who kissed Naoya) and Shino (who secretly has romantic feelings for Naoya), they embark on a summer vacation full of romance with a fireworks festival, camping, and Okinawa. 
 
Milika's younger sister Risa also appears, making the romance in this neo-standard rom-com heat up even more. A season two filled with summer and swimsuits is about to begin! 
 
(Source: Crunchyroll)