Yojouhan Time Machine Blues

Two absurdist romantic comedy anime where the focus is on time travel and the different paradoxes it could create. Time travel here works in a similar way as well, as there is just one single timeline where the different mysteries presented are basically created by the other travels to the past. Animation style is also experimental in both, the biggest similarity being the use of real-life imagery. Heck, they're both charming comedies that you shouldn't miss if you like quirky romcoms. (copied from my AniDB) 

Both have the premise of a person who travels to the past to meet their family and the different bizarre ocurrences that happen because of that. Both also have a similar style of dry humor, witty heavy dialogue and slaptick comedy. (copied from my AniDB recommendation) 

It is "kind of" season 2 of Tatami Galaxy. It follows the same characters but with a new and interesting plot. 

Both of these series feature Time Travel and are set in summertime. Tatami Time Machine Blues is even based on a movie called Summer Time Machine Blues making the titles similar. Both series also feature light romance elements. 

Both of these series are about Time Travel, are set in a somewhat modern Japan, feature a great expressive cast of characters that are a joy to watch. More specifically both are concerned with the consequences of the butterfly effect.