There's been no announcement of a second season for "Shimoneta," and it's possible that the show will never return. The first season originally aired in 2015, so it's been quite a while since the show's creative team was collaborating on the project.
Tanukichi has a crush on Anna Nishikinomiya, the Student Council's president, because he wants to be as pure as her Tanukichi would sometimes have problems supressing his dirty mind because everyone around him are sometimes too naïve.
How can you consider it complete? It ended chapter 13 right in the middle of a story. That chapter introduced new characters and was clearly the start of something new.