American-style supermarkets were... well, American. Big, large, super-sized- these were all synonyms, but the point was that this unfortunate Kamijou-san was overwhelmed by what he saw.
And thus began the classic Kamijou clan's shopping strategy. He paid zero attention to food names, oh yes; his eyes were on the prize: the price tag.
Yes, as like any other man limited by budget, his goal was quantity, not quality. In terms of frugality, he could not be beat.

The first aisle consisted of dairy products. Milk, cheese, cream, and more. They still had milk back at home, so Touma moved on to the next aisle which had rows upon rows of refrigerators.
Frozen foods were piled on top of one another; they all had shiny packages designed to attract hungry customers. But they too, were expensive. Additionally, he doubted their nutritiousness compared to fresh products.
The next aisle was entirely dedicated to all sorts of cereals, a detail that screamed out 'America' to Touma. Big, small, sugary, plain... the choices were endless. Unfortunately, his budget had no room for cereals; for all intents and purposes they were glorified deserts, and he had little money as it was for savory foods alone.
The next aisle had all sorts of canned products. From canned beans to canned fish to even canned chickens (much to Touma's apprehension). And, due to the inherent nature of canned goods, they were quite cheap. Several salsa and olive cans were on sale; taking two, Touma placed them in his cart.

The next aisle had all sorts of animal products from canned meat to chewing bone. Touma could not think of anything particularly lacking for Sphinx; he moved on the next aisle which had baby products. From dried formulas to luxurious diapers... truly, everything appeared to be accounted for.
Oils, sauces, and vinegars populated the next aisle. Touma remembered that they were out of sesame seed oil and bought cheap bottle of it. The next aisle had all sorts of condiments both sweet and savory: peanut butter, jams, jellies, mayonnaise, dressing, jellos, etc...
And then came carbohydrates. A bread basket on the side held various baguettes. Here lied the ultimate selling point for American-style markets: cheap bread. A long bread roll the size of his arm sold for only 99 cents due to it being a day old. Touma felt waves of gladness while placing multiple rolls in his shopping cart.

Then, he noticed a familiar brunette out of the corner of his vision.

"Misaka?"

"-Beh!?"

The girl spun around to see her idiot standing several feet away from her.
Wait, since when did he become 'her' idiot?

"What are you doing out here so late? Isn't it past curfew?" Touma asked as he walked up to her.

"Are you asking me why I'm past my curfew!?" Sparks of electricity began to arc around her bangs. She usually restrained her abilities in public with great self-control; of course, his presence now mucked up all her discipline.

"Well, aren't you still in middle school?"

"And you're still in high school, which also has curfews!" She exclaimed.

"Fair enough, fair enough... say, what do you have in your bag?"

"Eh? Oh, th-this?" Only now had she made a vague attempt at hiding her shopping bag behind her back. "This, uh, this is... for baking."

"...for baking."

"Yes, for a friend... a particular person who did a lot for me - not that you'd know him, of course - a someone who I at first tried to thank with some store-bought goods - a lot good it did, seeing that he wanted cookies baked by my hands while suggesting that I am that-sort-of-girl-who-clumsily-tries-to-show-her-appreciation, the nerve of that idiot - b-but not that you'd know anything about that, of course - well I had no choice but to bake something, now did I - a baked good that I couldn't even properly give - (doggone it why is he so CLUELESS!?) - well guess what, I'll just buy some more ingredients right now to make another batch - this time I'm making sure that you get them - I-I mean him, not you, you're not involved in this in any way, shape, or form, of course - but regardless, here I am, doing another shopping-"

Her uncontrollable rambling reached a point where she failed to realize until now that Touma, now bored with the (one-sided) conversation, had already left.

"W-wait!" She cried, noticing the empty space in front of her. "DON'T LEAVE IN MIDDLE OF CONVERSATION WITH ANOTHER PERSON, YOU JERK!"

All she managed to do, however, was to attract stares from other shoppers.

Touma went through additional aisles holding various items from pancake mixes to assorted expensive meats and delicatessen. The produce section, which took up an entire corner of the store, was of particular boon; from onion Vidalia to fresh strawberries Touma took whatever was cheap and plentiful.
Then an unfamiliar section of the market appeared; various balloons hung from the florist corner.

Come to think of it, wasn't it Index's birthday soon? Perhaps she'll appreciate some flowers. The price tags appeared quite reasonable for some of the bouquets...
He couldn't remember the individual connotations behind each colors. Figuring that yellow was a decent neutral color, he picked up several batches of a sturdy-looking flower.
Index would probably also want balloons, right? But he had no idea as to what balloon she would particularly appreciate. There was one in a shape of a car whose unique appearance intrigued him; but he wasn't buying a balloon for himself right now.

The only other balloon that caught his eye was one in yellow diamond shape. It resembled the center... 'thingy' Index had on her robe. Deciding that it was as good as any other, he reached for the string of the balloon which had a clamp that held the entire thing down.
Upon completing the transaction he realized that he was several dollars short; deciding that the cheese and the pickles were not essential at this time, he removed them from his cart.

Between holding the flower, umbrella, and the balloon he doubted his ability to hold the rest of the groceries; fortunately, he thought ahead and had brought a bag. It weighed heavily on his back due to multitude of cans and bottles within; he sincerely hoped that his bag would not tear during his walk back.
It was still raining when he reached the exit much to his disappointment. Opening up his umbrella Touma began his awkward trek home, feeling rather obligated to make sure his balloon stayed inside the cover away from the rain.

There are few greater discomforts than the texture of wet socks. The very action of walking itself was an adventure as Touma squinted through the darkness to see where the puddles of rainwater were along the sidewalk. The balloon appeared to be quite rebellious as it insisted upon roaming outside of the umbrella. He was often compelled to pause to adjust his arms for better comfort.

He was more than halfway home when a soft snapping noise reached his ear. The presence of the plastic balloon he felt against his temple was now gone. He spun around to see the balloon waltzing into the sky with total disregard for its new owner.
Touma, now completely indifferent to the fragility of his backpack, ran forward with all his might; the balloon, perhaps slowed by the rain and the wind, took its sweet time to climb into the sky. He reached his right hand forward and grasped for one of the tips of the balloon.

His reach was an inch too short.

Touma stood there in disbelief, watching the balloon climb higher and higher into the air until it turned invisible against the night sky.

...

His ears rang with his wild heartbeat.

...

He knew this was coming, of course. Anytime he did anything at all something had to go wrong. Such was his misfortune.
However, he could not remember the last time he felt this much disappointment.
But again, he was used to this. He turned around and began his defiant march home without a single backward glace.
His heart was heavy; he looked forward to seeing Index's amazed face in reaction to the plastic balloon. There was none other like it in the market... his home was mere two blocks away.

...

He wanted to kick a tree. He wanted to swear.
But he could not move; his entire body now felt ten times more fatigued. He did not even have the strength to say his classic catchphrase.
When he reached home, he noticed that he was still duly holding on to the limp string.

"Ne, Touma, these are beautiful flowers! I love Dandelions!"

So those were Dandelions, huh. This Kamijou-san only dealt in colors when it came to flowers.
Fortunately, Index certainly admired his gift.

"What's this for?" She asked, holding up the blue string.

"Ah... well, I bought a balloon, but it broke off." Touma scratched the back of his head. "Sorry about that."

"Well, that's alright. We can still use this clamp for laundry!" Index beamed.

Such an innocent smile...

Touma found himself smiling, too.