Are you still looking? I don't see Tosten Helgeson Nesja and family either, in the census in Valders, Manitowoc, Wisconsin or elsewhere. I'll add some family names; maybe that will help.
Are you sure Tosten/Torsten used the name Nesja in the USA? That "uh" sound at the end would be written with an e in Scandinavia.
EMIGRATION RECORD Depart Bergen, Norway 24 April 1867 Arrive Quebec, Canada 09 June 1867 Ship Name: Nordcap
* Helge Knudsen Næsje, age 52, farmer, Residence Valders * Sigird Olsdatter Næsje, age 52, wife * Ingrid Helgesdatter Næsje, 21, daughter * Ole Helgesen Næsje, 19, son * Torsten Helgesen Næsje 14, son * Ole Helgesen Næsje 12, son (yes, two sons, same name) * Kari Helgesdatter Næsje 9, daughter
Sometimes in the first years after arrival in USA a Norwegian immigrant father is enumerated with his patronymic name (or alternately his place name). So that would be Helge Knudsen or Helge Nasje/Nasja/Nesja/Nesje (or similar). Then the children are assumed to have his same surname, so Tosten/Torsten could possibly show up as a Knudsen/Knudson/Knutsen/Knutson in the 1870 census. His name could be spelled with a Th, or appear in an Americanized version (such as Thomas).
So there are a few ideas for parsing databases that might help volunteers to help you.