Disclaimer: This post is not meant to badmouth Kojen. It is merely an honest, and hopefully fair, portrayal of Kojen written solely for the benefit of other teachers thinking about coming to teach English in Taiwan.
I work in the adult department at Kojen. For any of you that have experience teaching English in Taiwan, you're probably saying, "Why in the world is an experienced teacher like her still working at a place like Kojen?" I'm going to discuss those reasons with you now.
Let me start by saying that Kojen isn't the best place to work for, but it certainly isn't the worst. And, believe it or not, there are reasons why someone would want to stay there. However, I firmly believe that these reasons exist within the adult department only. If you are serious about teaching kids, do not make a career of Kojen! It's okay to work there for a year or two when you're new to English teaching and you don't know what you're doing. There's a lot of materials to work with, and you'll get plenty of hours. However, one soon realizes that Kojen is a business, not a school that cares about the education of the students. Not only that, but the foreign teachers are treated as expendable resources. Actually, there is a cycle that exists within Kojen. Most of the English teachers that come to Kojen are either really unreliable and transient, or they stay for a year, wise up, and then leave. Then Kojen says, "Why should we waste time and money catering to the wishes of our foreign employees when they leave within a year, often before their contract is up?" However, what Kojen refuses to acknowledge is that they're the ones attracting those kind of foreigners with their low pay (at the time of writing, $590 NT per hour starting for kids and $580 NT per hour starting for adults) and lack of benefits. Also, raises and benefits are never given on time, although I will say that when you do finally get the raise it comes with back pay. Also, you will never have to worry about them trying to cheat you out of your paycheck or not paying you on time. This makes Kojen a reliable place to start working in Taiwan, but not a profitable place to work for long term.
If you want to teach kids long term, you can make way more money and get more respect somewhere else. However, if you're interested in teaching adults, you have fewer options. Unless you work for an adult language center or buxiban that offers test prep. classes (TOEFL, TOIEC, etc.), you won't find an adult buxiban that pays much more then Kojen. Also, there are not many adult hours available because more attention is given to the kids department. Some branches don't even have an adult department! However, I truly believe that the adult department at Kojen is pretty good. Granted, some branches supposedly aren't very good to work for because the management is pretty intolerable. But if you get a good AD (academic director), teaching adults at Kojen can be a satisfying experience. Unlike some other adult buxibans that have a system similar to gym memberships set up, at Kojen you have the same set of students for 7-8 weeks, This is great for bonding with your students and creating the right kind of classroom atmosphere. Also, there are a ton of materials and it's usually pretty easy to get help. But once you get to the point where you know what you're doing, you're left alone. You can teach the class any way that you see fit, as long as you're not doing anything to make people complain. If you want to give a test, give a test. If you don't want to do any tests, that's okay too. You can deviate from the book as much or little as you like. There's a lot of room for you to grow as a teacher and be creative.
So, this is why I still work at Kojen. My first year in Taiwan, I had no idea what I was doing. I started working at Kojen and learned a lot about teaching. I also quickly discovered that I hate teaching kids. At first I was only working at one branch. However, the adult department at another nearby branch had a few classes available, but not enough to hire another teacher. So, I started working at that branch as well. Now, after a year, I am firmly established in the adult department in two branches of Kojen, and both of them are on my work permit. Because I work at two branches, I have enough hours teaching adults to not have to teach any kids. It still isn't that many hours, but that's good for me because I just want to use Kojen to get my ARC and make my real money tutoring. So, if you're looking for a low stress side job to get your ARC, the Kojen adult department is an okay place to work. Otherwise, I wouldn't recommend it.