Guide By: Buronzu
Play with all 10 idols
This unlocks after you finish the game with all ten idols. As your producer rank goes up after each playthrough, you can begin to make duos and trios. This achievement requires at least five in-game years to complete.
Select all 16 songs
This unlocks after producing all 16 songs in the game and requires a minimum of three in-game years to complete, presuming you don't choose a song twice during that time.
Win all 4 seasonal auditions and succeed in celebration of the events
In March, June, September, and December, seasonal auditions will appear in the first slot of 'Special 2' auditions. They require image rankings of 9, 11, 10, and 12 respectively. You then need to attend the promotion on the 'fifth week' of that month, which only appears after successful completion of that month's seasonal audition. You don't need to fill up the bar to pass, you can just put your controller down if you wish.
Win the Super Idol audition
Get your unit to image rank 13, and complete the Super Idol audition in the 'Special 2' audition category. It will unlock on the night right after the audition.
Get A rank and the best ending at the Dome
You need to get your unit to at least Rank A for this. When you get to the final day of your unit's career, choose the option to tell them the truth. From then each character's dialogue is different, so I'll refer you to this guide. It's in Japanese, but the character's name is in English in the top-left of the page, and also in the top-right of your game screen.
Win 100 auditions
This achievement unlocks on the night after your 100th successful audition. This is very time consuming, as each audition attempt takes around 5-10 mins. This unlocked on my sixth playthrough of the game.
Get 100 Good or Perfect Communications
When you do a promotion, selecting certain answers will influence the outcome of the event and give you memories. This achievement will unlock on the night after your 100th successful (Good or Perfect) communication. Refer to the aforementioned dialogue guide under the "Best Ending" achievement for the correct answers for every situation. This unlocked on my seventh playthrough.
Get 100 Good or Perfect Lessons
This achievement unlocks after the final summary at the very end of a unit's career, just before it fades back to the title screen. You need to complete any of the lessons 100 times with your meter in the green or orange sections. To stop your idols from quitting the lessons early, get their tension down to yellow or blue levels and try to keep it there. This will also stop lessons from being blocked.
Get 100 Memories
Please see the "Communication 100" achievement. After almost every perfect communication, you'll be awarded five memories. Once the cumulative total from your playthroughs hits 100, the achievement will unlock on the night.
Reach Production Rank of Idolmaster
You need to achieve producer rank 10. To do this, finish each unit's career with a high image level, a high idol ranking (at least 'A' rank), and finish as many special auditions as possible. This took me seven playthroughs to unlock, though you could theoretically do it in five if you knew exactly what you were doing from the very start.