I do hope this continues onwards; the whole fanfic looks to be really thought out, especially judging from the notes after the passage.

Keep up the good work!

Well. Shinichi will definitely become the Detective Boys' favorite babysitter, assuming they even i/become/i the Detective Boys instead of something else. Ran will probably blame Shinichi for their interest in mysteries all but exploding, regardless. XD
If Sonoko finds out she'll be dragging tiny-Ran out often for girl days, on the excuse that living with only a guy is no way for a young girl's femininity to blossom properly, or some such tripe. Maybe she'll host girls-only sleepover's with Ai and Ayumi, too. *coos over cuteness*

Something like the "Power Shoes" would definitely suit and help a tiny-Ran, and maybe something like fingerless gloves with thick bands to match them for her hands - both to compliment the power-boost and to provide some protection, as part of why Shinichi only kicks objects soccer style is because he'll break his foot if he kicked a wall as hard as he kicks a soccer ball. No need to self-maim a chibi-Ran-chan.
Maybe Ran's alternative presence will give the Detective Boys more interest in modern Ninja in addition to mysteries? I'm sure there's a series she doesn't dislike that such gloves could be styled after to fake being fan-merchandise instead of a fashion choice. ("Fake fan-merch" being more easily assumed of small children than "dedicated life-long martial arts student with real equipment" even when said items are just as quality.)

Oh yeah, nothing quite as ego-busting as extensive child-minding, especially when your particular vein of ego-boosting-source is so inherently dangerous. Chasing after the mini-detectives, and learning how to explain things to teach and manage them without causing waterworks or tantrums, should certainly be quite helpful to teaching Shinichi how to interact with others better without coming of as quite so much of a jerk. Especially with a tiny-Ran to lecture him later on i/exactly/i what he did wrong with upsetting the other children.
She'll probably want pictures of her best friend with ducklings, though. It sounds adorable.
Oho. What if one of the actual Boys develop a crush on tiny-Ran? If she's clearly quite attached to and even "crushing" on Shinichi-san... *cues adorable chibi-death-glares* XD

And nothing is quite as heart-stopping or faith-shaking as genuine reasons to be terrified out of your mind for the lives of a group of small children you've grown attached to. Or even just one.

this would truly be really cool to see happen

Interesting idea. I like how she ran straight for Shinichi :D

Wow! That was... Brilliant! I love it! I'm saving this idea!

When I readed the title, I thought, that Ran was forced fed the poison, aftr Shinichi shrunk. But its interesting, looking forward to more!

Wow, this is really promising! You have some fabulous ideas for chapters to come and you write Shinichi and Ran really well. I look forward to reading more 3

Say what you want, Shinichi, you were the one originally supposed to be poisoned after all.

TSUKIKAGE ISLAND AHHHHH GOOD TIMES GOOD TIMES
#IDrawFanartOfThatCulpritAllTheTimeAndIDontKnowWhy

...anyway. I'll admit, this is probably the best rendition of the "Ran shrinks instead of Shinichi" scenario. You made it make a whole lot more sense than people usually do. Congratulations on being smart! :)

Nice take on the "What if Ran shrunk instead?" thing. I like it.