flumpool has unveiled the PV for their new song "Natsu yo Tomenaide ~You're Romantic~" via their official YouTube channel. 

Natsu yo Tomenaide ~You're Romantic~" will be released on August 5 in preparation for their first outdoor lives, "flumpool Manatsu no Yagai?LIVE 2015?FOR ROOTS?~Osaka Fields Forever~", that's scheduled to be held on August 8 and 9 at Oizumi Ryokuchi Park in Osaka. The PV has the theme "the will to produce new expressions," and you can see the members playing with their "individual color" and producing a "new flumpool".  

Source & Image: natalie
Thanks to minlilin for the tip!