They both feature friendships between two boys who meet by coincidence and end up having a great time together for their shortlived friendship. Though Setoutsumi takes place over a longer span of time and doesn't carry any dramatic circumstance in the movie version, the essence of two boys forming a bond with plenty of comedy and light hearted moments in between is shared. I thought of this movie while I was watching Cycle Cycle and recommend it, because it is just super fun and entertaining. The sort of friendship so commonplace in Japanese media like this, so if you liked it here, or just in general, then you can enjoy Setoutsumi. ^^
