I know a couple of people were curious about this, so here we go. The Absolute Worst Ending.
This occurs if you lose to NAZO in the IU Finals. Yamato has proven once and for all that he is truly superior over Kenji. ZetaPro sadly watches an encore performance of NAZO's God knows... Yamato then goes over to ZetaPro and rubs NAZO's victory in their faces. He's won the war. Upper-class bureaucracy has proven itself superior. It was his father's own fault that he chose an overrated commoner of a producer (who doesn't even deserve to be his rival) to carry on his obsolete morals. ZetaPro will always lose because they are low-class scum.
As NAZO accepts the IU championship trophy, Yamato plans to forever ruin the image of the middle class. He explains that their journey to the top wasn't easy, having to deal with smaller companies who resorted to cheating against them just because they were jealous of NAZO's success. Kenji is suddenly dragged on stage by Yamato's agents. Yamato claims that RyuuseiPro has just foiled ZetaPro's attempts to cheat its way to the top thanks to Kenji's production. He tried to sabotage NAZO's performances, destroyed their CDs in order to wreck their sales, edited his own idols' bland and meaningless songs in order to mask their lack of talent, and even resorted to sexually harassing them as punishment. In short, this commoner is a selfish scumbag who would pull any dirty trick in the book to win. The crowd believes his lies and heckles Kenji harshly. Yamato then reminds Kenji to hold up his end of the bargain...quit his career and passion in music and never come back. To further humiliate him, he even makes Kenji bow to his knees and proclaim Yamato his superior in front of everyone! A dejected Kenji is booed and jeered as he exits the stage. Yamato claims that will not stop him, though, as RyuuseiPro will continue to deliver Japan's greatest entertainment of all time.
As everyone returns home, Kenji gets an email from the President. He wants to meet with him and the idols tomorrow.
On the next day, Kenji and the idols arrive disheartened. The President has even worse news. Yamato and RyuuseiPro have taken over ZetaPro and he has declared himself the new producer. Everyone is shocked. Yamato then goes over to Kenji, claiming this is the position for a perfect elite like him. He banishes Kenji from ZetaPro and tells the idols to cut off all access to him...they will never be able to see or talk with him ever again, even Sakura, whom Kenji has known for the longest time. Yamato warns Kenji never to compose, play piano, or do anything regarding music again. Kenji already has become infamous among everyone in Japan after Yamato humiliated him in Tokyo Dome. No one is willing to listen to him anyway.
It's all over. Kenji has nothing left. His new friends, his musical talents, his desires, his good reputation, everything is gone. Kenji returns home a ruined man...
Once you begin Story Mode again, Kenji is seen in his bedroom, having awakened from a nightmare. Kenji is relieved that it was just a dream. That never happened. Today's a new day. He shakes it off and confidently heads to the office to begin his new career.