Taiellin
Слушайте, но у нас так же. Для одних ты Миша, а для других Михаил Андреевич, или просто Кулаков, или сосед из пятой квартиры.
Но если историю про Мишу рассказывает его друг - он вряд ли будет переходить в рассказе на Михаила Андреевича, для рассказчиков про Михаила Андреевича наоборот - вряд ли пойдет просто "Миша"

You're reading a Russian-written and/or set novel in which there's a hot Soviet spy (with blonde highlights, natch) called Ekaterina Ivanovna Smirnova. She hangs around Moscow and goes to Moscow Centre to do her work, where she's called Major Smirnova or Ekaterina Ivanovna. Then she has lunch with her friends, who start calling her Katya. In the evening, she visits her parents at their dacha and they call her Katenka. There, she meets her old grandmother and her sister who address her as Katyusha, and her sister's husband who calls her Katerina. Elsewhere, her workmates are enviously discussing her successes, stating that Katka has given herself too many airs.

No, you haven't gone mad. Nor has the author engaged in a stunning display of inconsistency. All of them talk to the same Ekaterina. You've just entered the world of the Russian diminutive.

There are at least 50+ different variants for "Ekaterina."note Ekaterinka, Ekaterinochka, Ekaterinushka, Katechka, Katekha, Katena, Katenka, Katenochka, Katenushka, Katenya, Katerinka, Katerinochka, Katerinushka, Katka, Katlya, Katrenka, Katrya, Katsha, Katunechka, Katunka, Katunya, Katusha, Katushka, Katya, Katyakha, Katyasha, Katyashenka, Katyashka, Katyokha, Katyona, Katyonka, Katyonochka, Katyonushka, Katyukha, Katyulechka, Katyulenka, Katyulka, Katyulya, Katyunechka, Katyunka, Katyunya, Katyura, Katyurka, Katyurochka, Katyuronka, Katyurushka, Katyusechka, Katyusenka, Katyusha, Katyushechka, Katyushenka, Katyushka, Katyuska, Katyusya.