Onion John is a man who lives on the fringes of society in a small town (Serenity) in the late 1950's. He understands English but is difficult to understand when he himself speaks. He believes in superstitions - as a lot of kids do. In fact, it is kids that help bring him into society - since typically kids don't judge and shun as much as adults.
The book is full of positive examples, like early on when Andy, who is Onion John's primary friend, is encouraged by his coach and his father that trying your best is more important than winning.
Andy's father becomes the link between Onion John and adult society since he's quite open minded. He believes it's okay to humor Onion John and understands that even if Onion John's dance didn't make it rain, it's okay if Onion John believes it. He's so good at humoring Onion John that he even fools Andy.
There are several pages about Halloween and some kids having an innocent party and Onion John introducing them to some ceremonial-type rituals such as scaring off any witches before they eat. It's nothing satanic; rather entertaining and as innocent as Onion John but if you're strongly opposed to Halloween then you might want to pick a different book.
A little less than halfway through the book we come to the crux. Andy's dad decides it would be nice to upgrade Onion John's shack for a real house. The entire community gets involved. They do involve Onion John in as much as possible, but it's easy to see (for experienced person) that they are assuming Onion John wants to change his substandard living. Onion John likes extra bathtubs in his living room. Mr. Rusch says, "It's not proper, or right, or civilized." (p. 104) ... "We're trying to get him to live normal and comfortable."
John does keep a gun over his stove that he uses for hunting. At one point Onion John, Andy and Mr. Rusch go hunting and shoot two birds although we never actually hear what they do with the meat, I assume it is eaten and not just for sport.
John has a statue of St. Stephen that he kneels before and prays.
Pages 118 and 119 are more hints that people are imposing their norms on Onion John when a group is having breakfast together. Andy indicates Onion John usually eats onions for breakfast. Mr. Rusch is appalled so John says he doesn't want any onions. Andy tries to stick up for his friend but Mr. Rusch argues that John doesn't want onions (because he said). Andy supposes he's only saying that to fit in and please others. Mr. Rusch wants to believe that he's changing to go along with his new style of living. They even find out his full name and start calling him by it.
So the home makeover gets under way - well before home make over shows ever existed - perhaps this book was the inspiration for Extreme Makeover. In contrast to Extreme Makeover, more along the lines of Habitat for Humanity, in this story the future home owner is part of the build team. But Andy observed that, "...Onion John was a waste of time on a job, and material. It took time to explain to him what to do. And when he got started, he broke things." (p. 124)
And it also doesn't help that John is so superstitious. He believes the shadows of the workers can not fall onto the foundation. (p. 126)
As you might have guessed, John's ignorance and inexperience eventually lead to trouble. And speaking of inexperience, Andy gets really upset with his dad when he makes plans for Andy to gain more working experience during the summer. This becomes the theme for the last third of the book - not whether or not John will change but how will Andy handle his own changes.
John is not completely out of the picture though. When John's inexperience with modern appliances causes a destructive situation the town joins together once again to help John. John is just that type of person, though, that has good intentions but he trips over his own feet. When the catastrophe is almost over John puts himself in the middle of danger to retrieve his prized possessions. The reading gets a little suspenseful but I don't think it would be too overwhelming for a child. It's more like organized chaos. There is a lot of confusion and by the time things get clear, a solution is already under way. (p. 162-163)
For teaching points, in a practical way, there is an algebra problem on thoughts or how figuring out what x is really impacts life and there is a lesson on how insurance works. But the biggest teaching points are the moral lessons: Do you help someone when they don't want help or don't know they need help and is there a point where it's okay to stop helping them? And what is the right way for a parent and growing child to reach decisions about the child's future. Above all there are deep lessons on respect. Not just a yes ma'am - no sir type of respect, but truly respecting other's opinions, ideas and beliefs and disagreeing with dignity. One part of the issue is a father who never realized his own dreams and wants to transfer those dreams to his own son.
Like many of life's problems, it's not handled well in the beginning. In this case it is handled so poorly that Andy enacts a plan to run away. Obviously this seems like an immature way to handle things. Through the process though, Andy matures. He recognizes when he's not being honest with others and, perhaps more importantly, not being honest with himself.
As you would expect, everything works out well in the end. The true test is whether or not the reader agrees that everyone gets a happy ending. Was the reader able to let go of their perceptions of what should be?
The ending seems to stretch on with extra pieces and parts and a fascinating look at a local custom called a fish drive. A lot of pages are spent on a lot of details, but it also provides insight into more of Andy's maturation process. The men drink something called applejack which could be something alcoholic but its portrayed as an adult tradition and really doesn't seem unusually issue-worthy unless you have a strong opposition to anything even vaguely alcohol related.
Perhaps the biggest question the book asks is Who am I? and several different people find an answer.