Essentially an izakaya is a Japanese tavern. But it's also Japanese tapas. And it's a Japanese gastropub. So perhaps the way to think of an izakaya is as a Japanese gastro-tapas-pub. Don't plan on having a 45 minute meal before a movie. Don't plan on going and having a starter, a main, and a dessert. Go planning on having a long, lingering meal over good drinks and better conversation with a group of great friends. Make an evening of it. Once you're in that mindset the rest is easy.
Throughout the Kampai! izakaya reviews you'll notice frequent mention of "bottle keep" - a common izakaya service allowing customers to leave behind unfinished bottles of shochu for future visits. It's a great business strategy, encouraging more drinking and eating - once you've ordered a bottle you're more likely to stay longer - and more frequent visits since you'll return to finish that last bottle (and likely order another to keep again).