The translation heavily depends on the intended context and fixing typos or supposed errors based on that context.
Given a search, there seems to be a manga titled "Senryū no Oshi" or works close but Sennyuu Sousakan wa Zettai ni New doesn't directly hit. secret mission sennyuu sousakan wa zettai ni new
Assuming a typo or variation, if one replaces or adjust for known manga,"Secret Mission: The Infiltration Operation is Absolutely New" doesn't find direct reference; adjust might reflect. The translation heavily depends on the intended context
"The secret mission of infiltration is absolutely new." "The secret mission of infiltration is absolutely new
The provided text seems to suggest the title of an anime or manga series. There is indeed a series titled "Secret Mission: Kōtetsu no Spy" or similar variations, but specifically, "Sennyū Sousakan wa Zettai ni New" could be interpreted directly or related to known works:
Or considering standard usage:
"Secret Mission: Infiltration Operation is Absolutely New."