Of course when you spend a lot of time with your students and form positive relationships with them, you may want to take a picture with them to keep for your memories. This is totally natural and there is nothing wrong with wanting a photo with the people you have spent much of your time and efforts teaching and helping. This is going to be especially true towards the end of the year when the reality sets in that you may not see your students again.
Although you might feel like there is nothing wrong with having a photograph with a student, the digital age has brought along with it a lot of questions and concerns over privacy, because once a picture is up on the internet, it could well be there forever. That’s why you need to be aware of the implications of taking photos with your students.
Japan has a law where pictures cannot be published without a person’s consent. In the case of students in K-12, their parents are the ones that need to give permission. While you may not (and probably shouldn’t) have any intention of publishing photos you take with your students, even taking a photo without the parent’s express permission could turn heads.
Some schools have agreements with the parents in advance that they will take pictures throughout the school year together, in groups and during class time. Preschools in particular send parents pictures of their students in the school having fun with their teachers. You may or may not be made aware of some parents’ preferences on this. I had a student in my class whose mother didn’t want any photos taken of her at all! We went on a school trip once and took a fantastic photo of all of the children in the school running across a field, but we couldn’t use the photo on the school’s website because the mother was adamant that no picture of her child could be published anywhere (even though in this picture you could barely identify the kid). The legal ramifications here can be pretty severe.
The same is true of your school using your image for their own publishing. Without your express permission, they cannot use you for their marketing, for instance. Be sure to check your contract before signing it as there may be a clause that allows them to use your image for marketing purposes or teaching materials. If you are really against this be polite and request that you would rather not, and since schools should already be aware of the right to image laws they will usually agree without issue.
Take note though, being in your company’s marketing may not be the worst thing if you get involved with it, and may help your future job prospects. There is an effect in science called the Mere-Exposure Effect, and it dictates that simply seeing something makes you like it more. Other schools and employers might see your photo and like you more at interview, and being okay with having your face in public can make you a more attractive prospect for a school with a budget for photography and marketing. Just a thought.
You don’t want to get in trouble for something like this. I taught alongside an ALT who took pictures with his students and published them on Facebook in his first month at the school, and when they found out (he also added a lot of the Japanese teaching staff from his school on Facebook) he got in a lot of trouble. Be careful, but if you have permission from the parents to take photos then you can feel free to get a couple of keepsakes and memories. We are all human and want to have nice photos to remember our favourite students. Just be sure to ask the parents first.