There's a sequel or Volume 2 for this manga called "Gelateria Supernova Royal Vanilla". I found the blcd on yaoiotaku site by chance but couldn't find its manga
https://www.yaoiotaku.com/forums/threads/52817-%E3%82%B8%E3%82%A7%E3%83%A9%E3%83%86%E3%83%AA%E3%82%A2%E3%82%B9%E3%83%BC%E3%83%91%E3%83%BC%E3%83%8E%E3%83%B4%E3%82%A1royalvanilla
Synopsis of Volume 2 got from Baka-Updates:
Volume 2: Gelateria Supernova royal vanilla
After meeting through an online dating site, Naoki and Tomoaki had a purely physical relationship for almost a year before they finally became a proper couple. Tomoaki graduated from college and got a job, and despite their busy lives, the two men have slowly but surely grown closer together. However, when Tomoaki is sent to Osaka on a business trip, they're separated for two whole weeks. Having never spent this much time apart, it only takes a small thing to cause big trouble. Naoki's never loved anyone before, and he soon realizes he's getting a taste of something new. Feelings that began in a gelato shop melt together in sweet harmony and turn to love... (Renta!)
Keep checking this link for Vol2 updates. there's a ch0 of Vol2 here added in April 2020
https://mangaowl.net/single/37791/gelateria-supernova?__cf_chl_jschl_tk__=5fb7b5ac76c51f3eea989b3fd8875b96d5e8b112-1597268467-0-AUnnauYZ0kFPShcwJDFCLaPdQ-TeYcUQ_z_e1XhFUnh_reQa0V4xSk0GxgaSyV_sOl8tDPt6wbPw5Ea1QjkBYdp8t6j7oH93cekknde7G-3R6nMPGIF3UsxsfCKRmtmUljNfryWb3D3XPsqgL_nrcw_8j72cc8fAZ5wr6qqPAFePKHubJWnaLVCvKgRIpfysdIKpoUZwpz1BVnTUNuDlVyt2UKoOHTmsQbgUppLWyv2arO_w17n4p3AqRYDD92hMJx7Ks206p0I1NG4MBXX7agnQgJR8ay3wW3NudGUDogPfmXLTcXm0TvGfat9nLYWIPgt56G_JA99aEKPJU_Zq1vQe-vlhC0bHDPyzV3N5F10V-hZ_uPFeCESlypuP8mt99w
Blcd cast!!! My fav
Furukawa Makoto x Satou Takuya
Gelateria Supernova