Present tense use is noted.
“Walks lazily”, I’m okay with the use of adverbs unlike some people, though I’m wondering if a stronger verb that implies his laziness would work. Maybe amble?
The two “because’s” tripped me up. Seeing a repetition of subordinators (because, if, as, when, etc.) usually grates on people’s reading because of the tempo—I think—unless it's intended as parallelism. There is a way to merge the second two sentences to avoid this awkward "because of...because", but I'm worried about loss of meaning.
Third sentence "feels" probably should be past tense in this case. Comma after
...he’s too lazy to change his course.
This might need expanding. He's supposed to be lazy, but there needs to be an illustration. The second paragraph gives a clear opportunity to see his laziness override his curiosity. Although it's shown slightly in this paragraph, I think Ryushi's peeking is contrary to his laziness here. Stare here could work, he stares for a second and then moves on ignoring the girl's excitement. Then again uninterestedness might not be the same as laziness. This is thy call though. Feel free to keep it.
a group of girls surrounding chatting happily around a desk somewhere in the middle of the class chatting happily.
Yuan is surprised by the question. He never thought that there existed a person in the school who didn’t know about the girl student, and that person was his best friend too. He hesitates, but asks Ryushi anyway, “You seriously don’t know what her job is?”
The two sentences in bold can merged with a very simple use of a (past) participial phrase. Yes, sneriously I don't know what her job is!
A pop idol
Oh. Come to mention it, I'm in the same boat as Ryushi here:
...and even more than that he can’t understand why would anyone would choose to be a fan of those people.
Also in that sentence "doing /that/ flashy stuff". "That" is acting as adverb here; those is the plural demonstrative pronoun of that and isn't used as an adverb. Sorry, got grammatical...
He listens to music as well, ...
Is this necessary? Most people listen to music; if it had said that he didn't, then I could've understood why it would be in there.
...We still have some hope," ...
Speak for thyself, everyone's dying, even Altares's (Altares' ?) dead. Okay back to being serious.
...but giving up will not bring about the result he desires.
Now, I know this isn't dialogue, but it sounds as though the stout man is saying this. Speaking of, a better distinction between man and stout man would probably be better. I'm not sure if they are main characters, but names would help along with the description of "stout man". Oh, Altares is a place. Well. Actually, rereading the first sense, it makes more sense. Just imagine some random soldier being like "Welp, that's it for Altares".
the Librarian
“Yo clients, wassup,” says a voice from the door. “The journey was tiring, but as requested, here, the eyeball of the Psychedelic Prism Dragon,” Ryushi says as he puts a box in front of a man who looks very much like the leader of the group.
“Mibuchiha, can you battle now? I have something for you to tend to immediately. You’ll be rewarded handsomely,” the chief says as he inspects the contents of the box.
First, I'm confused. Is Ryushi the voice from the door, or is that someone else? Is it Mibuchiha, or was Mibuchiha the one crying or the stout one? Here's how I see it:
Voice from the door: Ryushi, with surprising exuberance.
Leader: Mibuchiha
Stout one: ???
Crying one: ???
Second, I'm not a person who likes the author in their own work, unless they're just in and out, like a cameo, but this seems like an important role, so....
A dragon?
...You’re to intercept it and kill it before it reaches the Radiant Valley Altares.”
...and after a few minutes, Ryushi is in the air, falling right onto the flying dragon.
This spot would be a perfect chance for landscape description, so instead of Ryushi being teleported onto the dragon, have him teleported somewhere in Radiant Valley Altares and have to find the dragon. This spot made me realize the dearth of description. I would go back and describe the classroom—what's in it, what type (European or Asian ?), and some unique characters (this last one being optional); now, I know that they're minor characters, but it gives off the idea that these characters, with their distinct personalities, exist regardless of the story being told, that they self-sustained/ing. Maybe a description of the exterior of the school and the path that Ryushi was taking might also be a benefit. Also a description of where those soldiers of Altares were would be beneficial.
'library’
Noticing a motif here. So books are involved in some way. His powers might based on the contents of his library, that is the books he's read.
Where'd the shield come from? The library or did already have one? I'm not fond of "smashes"; thrust would work better because thou already have "with all his might", which would be redundant in conjunction with smashes.
Replace "complains" with said in the following dialogue tag. Also change "still moving" with "rising +'ly' adverb that denotes the slowness that follows after 'massive (?)' damage".
The dragon now identifies Ryushi as its opponent. It roars at Ryushi, and that roar produces a shockwave that he barely manages to dodge.
I'm trying to think of a way to edit out the sentence after "and" while also merging the two sentences:
"The dragon, which identified Ryushi as its opponent, roars at him..."
I just can't seem to accommodate that finally part. Hm.
Real grenades? Or magical grenades?
Just as the dragon finally realizes that the grenades are just only to buy Ryushi some time,
If this dragon can realize something, then it shouldn't have fallen for a trick. Now this is something that I've become aware of: an author treats their main character as the only capable of doing something and having their enemies for simple tricks like this. Sometimes, it's best to ask thyself: if I were in the place of my main character's enemy, and having the same information that my enemy does, what would I do? If it comes to mindless things, those can be written off as they can't think. This can be a mistake too.
It protects itself by projecting a wind shield...
What? An explanation would be nice here. The uses of "finally" stick out to me.
Deciding to murder it, Ryushi recites another incantation and throws a more powerful grenade just above the dragon
What was Ryushi trying to do before?
"Golden Chance" is a cliche, probably best to remove.
The dragon is badly injured from the attack
Show; don't tell.
Of course, that’s not something Ryushi can allow.
Of course.
It’s only natural for the strong to prey on the weak, and the dragon understands it all too well.
Remove this entire sentence. There is no way that this would work without the strong-weak cliche.
I would say try and rework the fight scene.
“Nah, no need. I don’t want her to feel bad making both of us help her. Besides, you’re busy right, Yuan?” Ryushi asks, brushing off Yuan’s suggestion.
That's a big assumption to me, but then again, Yumiko-sensei's (not to self: how would the genitive be made here?) character hasn't been fully established or developed.
he staff room is now empty, and Yumiko-sensei is the only one inside. Ryushi walks to her desk and takes a chair from the next one.
Remove now. Do Asian schools have desks in their break rooms? I think table would be better used here.
...noticing Ryushi, her heart suddenly beats a little faster. “Uh, Mibuchiha-kun is here too...” she says inside her.
First, grammatically speaking, "noticing" is a dangling participle. Second, I'm not a big of something like "her heart beats faster". I think we need to establish the characters before the pop star falls in love with protagonist.
Mibuchiha, do you mind if I teach her here?
I'm pretty sure there is an honorific that's used when a superior speaks of an "inferior". I'm pretty sure it is "kun", but I can't seem to retain the information on honorifics whenever I read about them.
“Well, yeah...nothing too heavy though,” Ryushi answers lazily.
Don't say lazily, say something like dragging his words.
The question surprises the girl student. She feels a bit embarrassed having her teacher asks someone that right in front of her.
Show she's uncomfortable/embarrassed, even if it's obscure to the characters. Fun fact: whenever I was in math class and taking a test, I would get nervous/anxious and, as a result, my stomach would make gastric noises. That's the sort of thing to think of when showing some obliquely/subtly.
“Eh? Don’t tell me...you don’t know there’s an idol in your class?” Yumiko-sensei asks; she’s getting really surprised as well.
.....
Yumiko-sensei just giggles and replies, “You’re not one to say. What a weirdo not to notice there’s an idol in his class.” They then return to their homes, both are still surprised inside.
Way to be professional, teach. So we've established our teacher is unprofessional and acts informally while still at her workplace; however, I would like to see what she's like inside the classroom to see if there's a difference.
The last part, I'm not sure if I would keep it. Rework it at least.
Summary: Add more description; rework the fighting scene and final snippet; don't state a character's feelings and don't reveal people's inner thoughts; finally, the character's feel like stereotypes, so work on developing them more.