The second day of hearings was notable for one defendant, the ferry's first engineer, admitting charges of criminal abandonment resulting from the crew's decision to escape the sinking vessel while hundreds of passengers remained trapped.
The other 14 defendants have denied all charges, including Captain Lee Joon-Seok and three senior crew members accused of "homicide through wilful negligence", which carries the death penalty.
The first engineer, identified by his surname Sohn, "will not be making excuses," his lawyer was quoted as saying by the Yonhap news agency.
Asking the court in the southern city of Gwangju for leniency, he cited Sohn's poor health and said his client had already made one suicide attempt.
The lawyer also argued that it would be unfair to place the entire responsibility for the disaster on the captain and crew.
"The defendants must be punished properly ... but I hope there will also be stern punishment for the company which turned the Sewol into a timebomb," he said.
A nationwide manhunt is still under way for Yoo Byung-Eun, the fugitive patriarch of the family behind Chonghaejin Marine Co -- the company that owned and operated the Sewol.
Yoo is wanted for questioning on possible charges of embezzlement and criminal negligence, as prosecutors investigate the extent to which the Sewol disaster was caused by a lack of safety standards and regulatory violations.
The Sewol was carrying 476 passengers, including 325 students on a school trip, when it sank off the southwest coast on April 16.
So far 292 have been confirmed dead, with 12 still unaccounted for as divers continue to search the submerged vessel for remaining bodies.