For all that the novel criticizes the systemic injustice that drives Junior to leave the reservation, the tone of the novel is rarely bitter or didactic. Instead, it is heartfelt, observant, and often deadpan. For example, in Chapter 4, Junior describes the two types of teachers he has on the reservation:
You can’t teach at our school if you don’t live in the compound. It was like some kind of prison-work farm for our liberal, white, vegetarian do-gooders and conservative, white missionary saviors.
Some of our teachers make us eat birdseed so we’ll feel closer to the earth, and other teachers hate birds because they are supposedly minions of the Devil. It is like being taught by Jekyll and Hyde.
There are entire academic subfields that revolve around the dynamic Junior is describing. However, instead of enumerating all the problems with an education system that brings White teachers onto reservations, Junior jokes about the way this system actually plays out in his own life. First he lampoons the "liberal, white, vegetarian do-gooders" who make him and his peers act like they are animals with the supposed goal of honoring their culture. American Indians as a whole may have a different relationship with the earth than White settlers, but they are not actually birds. The "conservative, white missionary saviors" are no better. They try to scare the children away from birds, telling them that they need to act more like White settlers in order to avoid going to hell. Junior's deadpan tone gives the reader the impression that he and the other children see through both of these performances. The conflicting ideologies the teachers bring to the school have both been used to prop up genocidal policies against American Indians, but to Junior, the teachers are mostly exhausting and ridiculous.
Junior's humor, vulnerability, and focus on his own experience of growing up all create the sense that the reader is reading an actual teen's confessional diary. The tone allows Alexie to explore the intimate human impact of major social issues. Junior is a "Part-Time Indian" dealing with the impacts of racism and poverty, and he is also a growing teen who experiences all these things while trying to get a date to the winter formal. His charming tone draws readers from all sorts of backgrounds into his life, which is at once utterly normal and distressingly traumatic.