St.Sebastian's HSS Koodaranhi is the first Higher Secondary School in Thamarassery Corporate, we started functioning on 24-08-1998 with 2 science & 1 Humanities batches. With the incorporation of commerce and computer science batches in 2000 & 2012 respectively, SSHSS Koodaranhi became the largest HSS in Thamarassery corporate with 23 teachers and 583 students.