I'm studying abroad just like you want to be doing. However, my parents were much more happy to send me away.
Can you ask your dad for a good reason for you to not go? Cuz I have a lot of reasons on why you should.
It's sad to hear that he doesn't want to send you to a new place. It's more than just living alone. It's growing up, becoming more worldly and less ignorant while learning a new culture at the same time. And I think you'll be living in a dorm, so no worries about being all alone. Although, I don't think you will be fluent within a semester... you'll need a lot more time there, trust me. It's the kanji that's the most difficult.
Anyways, I'll give you a list on why you should study abroad so you can tell your dad:
1. More worldly people are more respected. No one likes an ignorant fool.
2. People who are bilingual have been shown to be stronger in work-related issues.
here's an article on the washington post:
http://www.washingtonpost.com/wp-dyn/articles/A39338-2004Jun...Sure, "what good is being able to be not distracted?" he may ask. Well, what if you're in a work related situation where you need to focus on one task and finish it by the 11th hour and there's distractions everywhere you look? Other benefits apply.
3. Having experience in another country looks great on your resume. I don't know what kind of job you're looking for, but if you've studied in another country, the employer will definitely keep an eye on you.
4. Making connections. As in, lots of different people to meet and stay close to. These people may help you in your future as either a place to stay the night for when you visit again... give you a tip on a new job... help you find a place to live if you plan on living there... Or if you happen to meet an international business man with a high position, he can offer you an internship somewhere.
5. A new language means a new culture. This may relate to number 1, but learning a new culture gets you out of your own bubble/box and makes you grow up a little and see the world with new eyes. It really changes you for the better and you are capable of seeing your home country differently by the time you go home. Especially in a place like Japan, where ever you're from, I'm sure it's completely different. Tell your dad that what's a better way to make you more mature than spending a little bit of time in a new country?
Has your dad ever been abroad before? It sure doesn't sound like it. If you can't convince him then have him talk to your Japanese professor. I sure your professor knows a lot about studying abroad in Japan.