Mr. Idol

Both are about dreams of being an idol, and a person who sabotages their 'honest' efforts :)

SHARK is all about a band coming together and making a comeback after the death of the lead vocalist. The main character is another vocalist, like Eugene, that needs to step in. However, in SHARK, the focus is how the bad-tempered "God-sent" vocalist learns to get along with the rest of the band and helps them Keep Walking forward to achieve their dreams. If you liked Mr. Idol, definitely check it out.

Minor Spoilers: SHARK's ending is a bit sad but beautiful. Also, the sequel just derails everything, mostly.

Both about the making and debut of an idol band containing men with troubled pasts. Both have big labels trying to stop them.