from typing import Counter


def nouns_after(tokens, target_word):
    """Return a counter of the nouns which follow the target_word."""
    nouns = []
    last_word = ''
    target_word = target_word.lower()
    for word, tag in tokens:
        if last_word.lower() == target_word and tag.startswith('NN'):
            nouns.append(word.lower())
        last_word = word
    return Counter(nouns)