The series that fits the "Tomo" keyword and is most famous for the "Girl trying to be seen as a woman by her childhood friend" trope is Feature Article: The Real Series Behind the Search Title: Tomo-chan wa Onnanoko! – The Modern Classic of Gender Bender Romance Opticraft Minecraft Windows 7 - 3.79.94.248
However, it is important to clarify that this specific string of words is likely a derived from machine translation. There is no official manga, anime, or novel with this exact name. Shinseki No Ko To O Tomari Dakara Dub Work Direct
Based on the keywords, you are almost certainly looking for the hit comedy manga series (Tomo-chan is a Girl!).
If you stumbled upon the phrase "Shinseki Nokotowo Tomari" while searching for a romantic comedy manga, you were likely looking for (English: Tomo-chan Is a Girl! ).