Making an original animation is difficult. Scratch that, making an original story is difficult. You're going to be judged and thrown comparisons at every which way you look. Influences and inspirations are all around us. People become storytellers because at one point, they were so captivated by a story, that they too, want to entertain others. There is no such thing as a completely original story anymore. Some one is always going to find some way to connect your story to another one. And when you try to fight that and become "unique" you end up spending way too much time trying to be different, that you forget how to tell a good story. Telling a story isn't about being unique, it's about expressing a story you want to write. Something that captivates your creativity. There's always going to be people who do not like what you do, who try to find fault, but at the same time, there's going to be people who will love what you do. Don't try to please everyone, because you just can't.
Onto Kaigan itself. It's an original, indie anime done in Flash. The style and overall look does come close to Inuyasha. But that doesn't make it an Inuyasha clone. It just means that it was an inspiration. There's nothing wrong with that. The characters are different, the scenario is different and the first episode is barely 5 minutes. You can't judge an entire story on something so short. The animation and line art is exceptionally clean, the audio work is above average and the opening sequence is extremely catchy. It's a beautiful show to watch. The interactions, while some may be shallow, are genuine. High school girls do act nosy, they like to poke fun. The first episode introduces us to the basic characters and touches on some of the lore. You are actually curious to wonder who the boy in the beginning was and what his connection with Akari is. While the episode is very short, there are a lot of things to take not on and think about. The tree doesn't bloom anymore, why? They are going to meet when the tree blooms again, so what's the connection and importance?
Some of the voice actors had some quality issues, nothing too big, but it can be a bit noticeable at times.
It's hard to get into the first episode completely because it doesn't feel like an actual episode. It just feels like the first part of the episode before the break happens. That could be a problem, and hopefully in episode, that won't happen. When telling a story, it's best to look at episodes as chapters in a book, there has to be a beginning, middle and end. It's all relevant. The end doesn't have to finish up what was brought up in the beginning, but it should be a lead into the next episode after establishing what the beginning set out to do. In this case, it was to introduce us to the lore and some of the characters. But there wasn't enough interaction to properly introduce the characters, specifically Akari. She was mainly the victim of being bothered, she didn't really do much other than day dream. We still don't know much about her personality or her motivation. A lot of that gets developed over time, but in the beginning, there should be enough established to either like or dislike the character. Right now, we're all basically "meh".
There doesn't have to be immediate action, so that's not an issue. Action without context is pointless. So if there's no action in the first episode, there better be an emphasis on character/plot development.
Overall, it's a very good start. The art is cleaner than most, the animation was sporadic. Meaning it only happened in short bursts. The anime portion, the electricity bits and other anime like memes are fine. They're not my personal taste, but I don't think it kills the episode. It felt out of place to me, but considering the style and influence, it's fine.
You tell the story YOU want to tell. Don't adjust your story because someone is telling you to be unique. You will never tell the story someone wants you to tell well, because it's not what YOU know. As long as the characters and the plot take their own turns and develop in their own way, you'll be fine. The power of love thing is a very anime esque theme, but who cares. That's what you want to utilize. The best story you'll ever write is the one you want to write. If you ever start compromising, that's when you skills will rot and you'll lose touch with who you are.
Listen to the technique advice given to help you explore your story. But don't change plot points for the sake of impressing/satisfying 1 or 2 people. For the next episode, try working on incorporating more actual animation, body language, walking, background animation, etc. Don't rely too much on high quality non-moving frames for dialogue with 3-4 frames for a rapid burst of movement. Try your best to make characters react naturally and smoothly. The talent is there, you got this going, now move forward and make episode 2 that much better. It's off to a good start.