Pupils wishing to attend a high school in a district other than the high school in the district in which they reside shall obtain the consent of the board of school directors of the district or joint school of the area in which such high school is located before attending the same. Pupils desirous of having their tuition paid in a high school in another district shall secure written approval from the school board in the district or joint board in the district or joint board of the area of which they are residents. The board of school directors of the district in which any such pupil resides may enter into a written agreement with the receiving district for the attendance and tuition of the pupil.