The second season of Kanojo, Okarishimasu. 
A hopeless college student, Kazuya Kinoshita, meets a graceful rental girlfriend, Chizuru Ichinose, and ends up introducing her as 
his girlfriend to his family and friends. Time goes on with Kazuya unable to tell the truth, as he's surrounded by devilish ex-girlfriend Mami Nanami, who keeps coming back to tempt him for some reason, hyper-aggressive provisional girlfriend Ruka Sarashina, who doesn't know how to take no for an answer, and super shy but diligent and hardworking younger rental girlfriend, Sumi Sakurasawa… beautiful girlfriends of all types! The pub, the beach, hot springs, Christmas, and New Year’s… Having gone through these challenging events, Kazuya's feelings for Chizuru keep growing stronger. But she reveals a shocking truth that threatens to shake their "relationship" to the very core!
 
(Source: Crunchyroll, edited)

Episode 1 - Rent-a-Girlfriend

Episode 2 - Ex-Girlfriend and Girlfriend

Episode 3 - Beach and Girlfriend

Episode 4 - Friend and Girlfriend

Episode 5 - Hot Springs and Girlfriend

Episode 6 - Girlfriend and Girlfriend

Episode 7 - Provisional Girlfriend and Girlfriend

Episode 8 - Christmas and Girlfriend

Episode 9 - Lies and Girlfriend

Episode 10 - Friend's Girlfriend

Episode 11 - Truth and Girlfriend

Episode 12 - Confession and Girlfriend

TMS Entertainment

DMM pictures

Studio Comet

Kodansha

Mainichi Broadcasting System

Rent-a-Girlfriend Season 2