If you're looking for anime similar to Koitabi: True Tours Nanto, you might like these titles.
Chizuru loves Yuudai; Yuudai loves Chizuru. Yet neither of them can say it clearly because each is uncertain about the other’s feelings and is afraid of being hurt. Trapped by their insecurities in a relationship that’s going nowhere, they drift further and further apart. While Chizuru thinks this is the end of the road, Yuudai struggles desperately to overcome his cowardly nature before he loses what is most important to him. There are two stories to every relationship, but can love survive if they don’t meet halfway?
At the time of writing, I have only seen the Youji/Chiaki chapter of tours, so that is all I can base this rec on.
On to business- Both shows are not average tv shows, but rather specials or OVAs. Furthermore, both are about relationships that are full of misunderstanding. An obvious theme in both is communication. The set up is very similar- one episode tells the story of one side of the story, a second episode tells the other person's side.
Tokyo Marble Chocolate is an hour total, so while still not much time for characterization, there is more present than in the 15 minutes (total per couple) in Tours. That said, both are only meant to be snapshots of a single point in a relationship- they both show us the make-or-break moment every relationship goes through. If you liked one, definitely give the other a try!
Risa is a high school girl with zero experience in romance. Meanwhile, a boy named Yuugure is the most popular student in Risa's school year. Even though the two have had no contact with each other in the past, they find themselves at school at the same time one night.
Both contain short love story/stories that manage to tell a complete yet somewhat shallow tale of people in love. Due to the short run time, they ommit a lot of character and relationship developement but those OVAs do just enough to convey the message they try to put across to the audiance.
30-year-old housewife Azu Takamori has opened a nail salon. She feels her husband Junpei does not love her as a woman, but goes about her daily life as normal. Then, Junpei's adultery comes to light.
Based on Naka Fukamachi's illustration book, Fukamachi Naka Gashou Honobono Log ~Taisetsu na Kimi e~. The anime offers hearwarming peeks at the lives of close couples and families.
Qiao Anhao and Lu Jinnian had secretly longed for each other for thirteen years, and now that there's a possibility for them to be together. Even though the circumstances may be unconventional, neither one can refuse their inner desires any longer. Hurled into a false marriage, Qiao Anhao treads carefully towards the cold and reclusive Lu Jinnian, but after years of near-missed opportunities and deep misunderstandings, how could their last shot at love possibly run smooth?